FirebaseUI for Android v0.4.1

This release fixes a number of authentication bugs/issues in the 0.4.0 release, including:

• #121
• #124
• #142

This release also updates the versions of FirebaseUI's transitive dependencies:

• Depends on support library v23.4.0
• Depends on Google Play Services / Firebase 9.0.2 (which contains critical bugfixes)

Additionally there are various stability fixes, and increased test coverage.