nimble allows installing package with same name
When installing two packages from different sources and different authors but with same name, it works if the package which gets installed has a greater version number.
~~The~~ One problem is that `nim` doesn't support loading the package anymore.

Example:
1) `nimble install https://github.com/ephja/lzma` installs `lzma@0.1.0`
2) `nimble install https://github.com/tim-st/nim-lzma@#test-nimble-version` installs `lzma@0.1.1`
3) in nim `import lzma` fails with `cannot open file lzma` now.