Add support for reading compressed binary
Merge branch 'compressed-binary' of github.com:andreionut/erlang-etf into andreionut-compressed-binary

Conflicts:
	lib/erlang/etf/terms.rb
Adding read/write support for COMPRESSED external format.
Spec tests for Erlang::ETF::Compressed.
Adding ruby 2.1.1 for travis and adding coveralls configuration.
Don't use bundler_args for travis.
Release version 1.1.1, adding support for compressed terms.