Add license field to gemspec
Generate coverage info
Clean up unit test
Git-ignore coverage info
Set up integration test for pretty-printing GLib
Catch syntax errors when building classes
Create appropriate expected GLib result
Don't skip IConv by default

The result of this is, oddly, that building IOChannel no longer fails.
Depend on gir_ffi 0.7.1

GirFFI 0.7.1 allows GLib::IConv to be built.
Properly setup methods with unsafe names (like GLib::IConv#_)
Depend on gir_ffi 0.7.2

GirFFI 0.7.2 removes the separate get_gtype methods generated for each type.
This means the generated code for each class is now constant.
Ensure line break after printed module

If the code is written to a file as-is, this will ensure the file properly ends
in a line break. This is nice for tools like Vim and Git.
Make Travis CI run build on Rubinius
Update gir_ffi dependency

In particular, ensures boolean constant values are found
Gracefully handle failures pretty-printing constants
Update expected output for GLib
Only run unit tests on Travis

The integration tests are too specific to a particular version of GLib.