First implementation of #merge
Add tests to #merge
Update documentation
Format can be passed as a string or as a symbol. Fixes #23 #24 #25
Only use libxml-ruby with mri
Fix travis build
Split tests
Use downcase format to find template
Merge branch 'merge'

Conflicts:
	CHANGELOG.md
Bump to 0.3.1
When using child with a nil value, don't raise but return nil
(Close #26)
Merge remote-tracking branch 'upstream/master'

Conflicts:
	lib/rabl-rails/library.rb
	test/render_test.rb
Temporary fix