Fix universal gem installation issues

[jaym]

Trying to install win32-api on windows 64-bit ruby since it is published as a universal-mingw32 gem instead of x64-mingw32.
This patch should fix #3066

[indirect]

Thanks for the patch! Can you write a test, or at least describe how to test this, so we can make sure that it's actually fixed?

[jaym]

Happy to write the tests, probably goes in https://github.com/bundler/bundler/blob/master/spec/resolver/platform_spec.rb?
The case this covers is where the gem has a universal cpu

Any ideas why travis is not running? I wasn't actually able to run any of the specs on windows and was hoping I could see if I broke anything.

[indirect]

Travis isn't running because you created a branch whose name isn't in the travis whitelist, I think? You could add "universal" to the branch list in .travis.yml in a separate commit that I won't cherry-pick, if you like.

[jaym]

I'm not sure if that's the reason, but let's give it a shot.
Travis should build PRs against branches that are whitelisted, and master is whitelisted.

[jaym]

Looks like it worked. Anyway, specs added

[indirect]

awesome, thanks!

[indirect]

Cherry picked as bd078f2 and b7d5d90.