title: Adding a library Android-studio
body: <p>I'm having trouble when i add achartengine-1.1.0.jar in my project. 
  When i add </p>
  
  <pre><code>compile file('libs.achartengine-1.1.0.jar') 
  </code></pre>
  
  <p>in build.gradle, Gradle shows the following message :</p>
  
  <pre class="lang-none prettyprint-override"><code>Gradle: A problem occurred evaluating project ':NativeCharts'.
  Cannot convert the provided notation to an object of type Dependency: /home/***/NativeChartsProject/NativeCharts/libs/achartengine-1.1.0.jar.
    The following types/formats are supported:
      - Instances of Dependency.
      - Strings/CharSequences, e.g. 'org.gradle:gradle-core:1.0'.
      - Maps, e.g. [group: 'org.gradle', name: 'gradle-core', version: '1.0'].
      - FileCollections, e.g. files('some.jar', 'someOther.jar').
      - Projects, e.g. project(':some:project:path').
      - ClassPathNotation, e.g. gradleApi().
    Comprehensive documentation on dependency notations is available in DSL reference for DependencyHandler type.
  </code></pre>
  
  <p>Thanks in advance.
  Fab.</p>