title: Gradle module and git submodule
body: <p>I have a library project called toolkit with two modules <code>core</code> and <code>database</code>, with this config:</p>
  
  <p>settings.gradle</p>
  
  <pre><code>include ':core'
  include ':database' 
  </code></pre>
  
  <p>core build.gradle</p>
  
  <pre><code>dependencies {
      compile 'com.android.support:support-v4:20.+'
      compile 'com.jakewharton:butterknife:5.1.+'
      compile 'com.google.code.gson:gson:2.2.+'
      compile 'uk.co.chrisjenx:calligraphy:0.7.+'
      compile files('libs/flurry-3.4.0.jar')
  }
  </code></pre>
  
  <p>database build.gradle</p>
  
  <pre><code>dependencies {
      compile project(':core')
  }
  </code></pre>
  
  <p>it`s ok when run my tests at this library project, but i want add this library as a git submodule on other project, this project have the follow configuration:</p>
  
  <p>settings.gradle</p>
  
  <pre><code>include ':app-tablet'
  include 'libraries:float-hint'
  include 'libraries:toolkit:core'
  include 'libraries:toolkit:database'
  include 'libraries:twoway-view:TwoWayView'
  </code></pre>
  
  <p>app build.gradle</p>
  
  <pre><code>dependencies {
      compile 'com.astuetz:pagerslidingtabstrip:1.0.1'
      compile 'com.google.android.gms:play-services:+'
      compile 'com.j256.ormlite:ormlite-android:4.48'
      compile 'com.jayway.android.robotium:robotium-solo:5.2.1@jar'
      compile 'com.squareup.dagger:dagger:1.2.+'
      compile 'com.squareup.picasso:picasso:2.1.1@jar'
      compile files('libs/YouTubeAndroidPlayerApi.jar')
      compile project(':libraries:float-hint')
      compile project(':libraries:porquenao-toolkit:core')
      compile project(':libraries:porquenao-toolkit:database')
      compile project(':libraries:twoway-view:TwoWayView')
  }
  </code></pre>
  
  <p>and when I try compile i get the follow:</p>
  
  <pre><code>$  gradlew assembleDebug -d
  
  12:10:46.283 [ERROR] [org.gradle.BuildExceptionReporter] FAILURE: Build failed with an exception.
  12:10:46.285 [ERROR] [org.gradle.BuildExceptionReporter] 
  12:10:46.285 [ERROR] [org.gradle.BuildExceptionReporter] * Where:
  12:10:46.285 [ERROR] [org.gradle.BuildExceptionReporter] Build file '/path/libraries/toolkit/database/build.gradle' line: 16
  12:10:46.286 [ERROR] [org.gradle.BuildExceptionReporter] 
  12:10:46.286 [ERROR] [org.gradle.BuildExceptionReporter] * What went wrong:
  12:10:46.286 [ERROR] [org.gradle.BuildExceptionReporter] A problem occurred evaluating project ':libraries:toolkit:database'.
  12:10:46.287 [ERROR] [org.gradle.BuildExceptionReporter] &gt; Project with path ':core' could not be found in project ':libraries:toolkit:database'.
  12:10:46.308 [ERROR] [org.gradle.BuildExceptionReporter]    ... more
  12:10:46.308 [LIFECYCLE] [org.gradle.BuildResultLogger] 
  12:10:46.308 [LIFECYCLE] [org.gradle.BuildResultLogger] BUILD FAILED
  </code></pre>
  
  <p>I know the problem is about paths <code>:core</code> and <code>libraries:toolkit:core</code> but how solve this appropriately?</p>