The generated POM file of google-material-typeface is missing version for dependency of iconics-core
Hi Mike,

I start having some issue build my project once I have my personal maven repo setup. The issue is in the generated POM file in google-material-typeface,  as the following:

```
<dependencies>
  <dependency>
    <groupId>Android-Iconics</groupId>
    <artifactId>iconics-core</artifactId>
    <version>unspecified</version>
    <scope>compile</scope>
  </dependency>
</dependencies>
```

which is causing the error whenever I build: 

Error:A problem occurred configuring project ':app'.

> Could not resolve all dependencies for configuration ':app:_debugCompile'.
> Could not find Android-Iconics:iconics-core:unspecified.
>      Searched in the following locations:
>          https://jcenter.bintray.com/Android-Iconics/iconics-core/unspecified/iconics-core-unspecified.pom
>          https://jcenter.bintray.com/Android-Iconics/iconics-core/unspecified/iconics-core-unspecified.jar
>      Required by:
>          XXX:app:unspecified > com.mikepenz:google-material-typeface:1.2.0.1

This is happening only when my current project depend on another artifact that also requires google-material-typeface.
