Closes #16 - Adds better error messages for invalid cards
Update README.md

Styling changs
Cleaned up error messages
Merge pull request #19 from stripe/fix-16

Closes #16 - Adds better error messages for invalid cards
Added ordering for "next" behavior in view
Reordered errors
Merge pull request #21 from stripe/fix-15

Added ordering for "next" behavior in example payment view
Fixed typos
Test with Robolectric and set up Travis.

Reorganized and cleaned up the project resources a bit, mostly
in the example project. Had to move tests out of the library
project and into the example app, as Robolectric currently has
problems with library projects, but I'll move them back when
that bug is fixed.

Updated the bundled version of stripe-java to 1.15.1.

Builds in both Eclipse and Android Studio just fine.
added visibility modifiers, reordered methods to follow checkstyle standards, added builder pattern to Card model
resolved getters used internally in Card
Merge cleanup/bugfixes