Merge pull request #50 from ddrone/last-patches

Now dependency solver will consider only last patch version for every minor branch
Made elm-get compile with latest changes to Elm
Merge pull request #52 from ddrone/source-dirs

Made elm-get compile with latest changes to Elm
Merge branch 'dependencies' of https://github.com/elm-lang/elm-get into semver-check
Factored out function which checks correctness of version number to top level