title: Cocoapod "pod spec lint" CompileSwift returned an unsuccessful exit code
body: <p>I'm trying to create my first Cocoapod and I've set up my pod just fine so far, however when I try to lint or push, I get a bunch of build errors.
  The pod which contains swift code utilizes the sqlite3 library.
  I've linked it to the build phase of the Xcode pod project and I can build fine from there, but when running <code>pod repo push</code> on my pod, it tries to build and fails with a bunch of "use of unresolved identifier" errors, presumably from not having the dependency.
  I have also added <code>s.library = 'sqlite3'</code> in my podspec file but no luck.</p>
  
  <p>Here is a snippet</p>
  
  <pre><code>- ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:51:16: error: value of type 'String' has no member 'isValid'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:61:16: error: use of unresolved identifier 'sqlite3_bind_null'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:61:55: error: use of unresolved identifier 'SQLITE_OK'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:62:41: error: use of unresolved identifier 'sqlite3_errmsg'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:67:16: error: use of unresolved identifier 'sqlite3_bind_int'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:67:76: error: use of unresolved identifier 'SQLITE_OK'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:68:41: error: use of unresolved identifier 'sqlite3_errmsg'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:73:16: error: use of unresolved identifier 'sqlite3_bind_text'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:73:95: error: use of unresolved identifier 'SQLITE_OK'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:74:41: error: use of unresolved identifier 'sqlite3_errmsg'
  - ERROR | [iOS] xcodebuild:  SQLift/SQLift/Classes/PreparedStatement.swift:79:16: error: use of unresolved identifier 'sqlite3_bind_double'
  </code></pre>
  
  <p>I'm still new to creating pods and I'm not too sure how to fix this, any help would be appreciated.</p>