Add FastSpeech2
This pull request **introduces 10 alerts** when merging d35774b84dfad93f2827042f1ae542c009e5f287 into 3aa708844396027f3a2b6f8b0af9690a8dfe167d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-b05f40edfa8d9a2828f8e1237a16727010dac7fe)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 9 alerts** when merging c00552371a3f9c00b19b2eeabdbab09ee29dbe1d into 6962f75547e7ac2bb576f4e5a862b38d815ed79d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-98a2b7bf5cf445193b6af66863529c3de9f3d825)

**new alerts:**

* 4 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Syntax error
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 1b9ef8470748e62db77551db7333c04f17d54a9e into 6962f75547e7ac2bb576f4e5a862b38d815ed79d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-4ba73554a3724123162b329c5c99cb00299ce8a1)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging d663b88ebafbcc6afb8d95ff1ec405195859da54 into 6962f75547e7ac2bb576f4e5a862b38d815ed79d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-98eef409ab266f55d99d916fb2737156e93c5660)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 9e9b840a5e96d05aebaab71e326df4948badce16 into 6962f75547e7ac2bb576f4e5a862b38d815ed79d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-a0e1dab515a3e735f6881c6ffca9e0222690ece2)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 3b1bb17cbf127c66b0a24174dedcdcedc9903248 into 6962f75547e7ac2bb576f4e5a862b38d815ed79d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-a51a5689d9878612ab066bfcfd8c17a7c11e808a)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 5442bafc89680b94b3581cccaf987c727e3769c8 into 3aaaa0e4f53a92fbbe0166b3201113b7fd9006e5 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-9a88941f8f5ad8ab17d4698b6e0e4fe93f943d1f)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging d05ca8570c822f06f0227cf4706c92db1d5d7005 into 3aaaa0e4f53a92fbbe0166b3201113b7fd9006e5 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-62becc42c6b32c82cdaa4f328f6c131cb9049a63)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging a93f523205ee06a03bf14d9cfb6e784e302a9fba into afcce9a66502875e2c1f9646efb17aca5c48db20 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-56d32e6cd5586e82124e36f5524ef8bce4e5f4d8)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging e484f6276696b5125875dee6dfeeb100440076cc into 52121810b428e011666e656d313b42c954def26b - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-e07bb6a9f2ad1f17eb89475e0cada88146493a36)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 8284e4134ab0fd92f88c0ecc1bd7214f50f7a33b into 52121810b428e011666e656d313b42c954def26b - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-d80ad44a0b6e09803c5f61949dd84ad2b80c93c7)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 9f684b90d71d3f60a733ed06629ae1bd27dcacc9 into 52121810b428e011666e656d313b42c954def26b - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-1858a2254138ff619696f16adc1bfad403da44a6)

**new alerts:**

* 5 for Unused import
* 2 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 11 alerts** when merging bdf64ddf186faf5dc22243dcce9d5d6b8c203d2d into 2d68c8e7b872cb9776b8d7d7ae60d4bbcd3f7793 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-1d9b0ef4072a784253bfaea54535a05e5979a542)

**new alerts:**

* 5 for Unused import
* 3 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 11 alerts** when merging e3fea9ef21a235e8d6fe2aeb81ef84376fea0b44 into 54e6f6ee688f09810d3e54661275fd5c8718db00 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-99cc9a83731171f43b63627dd14613a3782094c9)

**new alerts:**

* 5 for Unused import
* 3 for Unused local variable
* 1 for Unnecessary pass
* 1 for Module is imported more than once
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 4cb225ec3f5eca12850565e7d412275467a4ff06 into 54e6f6ee688f09810d3e54661275fd5c8718db00 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-86d825f760a7d21b89d1b486296a65a045323511)

**new alerts:**

* 5 for Unused import
* 3 for Unused local variable
* 1 for Unnecessary pass
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 10 alerts** when merging 6172b00e21e2e273145482b032467ca9d82f7315 into 54e6f6ee688f09810d3e54661275fd5c8718db00 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-fceca5594316a6cb01ea25250d833697b36ee3c1)

**new alerts:**

* 5 for Unused import
* 3 for Unused local variable
* 1 for Unnecessary pass
* 1 for &#39;import \*&#39; may pollute namespace This pull request **introduces 1 alert** when merging 5730d2de3ccb944071a294608bfd19ba08cf6b2e into fbc5c2b4033896b75f643cf169976c1d38505d65 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-5c42a1b171dbb22c70d753c3869556c6f643bd98)

**new alerts:**

* 1 for Unused import @redoctopus, the PR looks good to go. Feel free to approve and merge.