erlware/relx — pull request #233 by tsloughter (2014-10-18 18:02:44+00:00)
Title: fix function defs for function that take vsn(), which can be an atom

Since type `vsn()` can be an atom:

```erlang
-type vsn() :: 'NO_VSN'
| ec_semver:semver().
```

Some functions were not properly handle the cases where it was.