deep_merge

• Added the possibility to @derive [DeepMerge.Resolver] if you want your custom structs to also easily be deep_mergeable
• added type specs
• Changed elixir support to ~> 1.6

Considered feature complete (tm) - unless you come with great feature ideas of course ;)

Initial release

• Remove warnings when run with elixir 1.4.0-rc.0

• Remove compile warnings on elixir 1.7
• Remove 1.2 from the build matrix (was getting big, should still work)