Enable Travis and AppVeyor CI

[r9y9]

This PR fixes a windows compilation issue (r9y9@677f5df) and enables travis and appveyor for windows/linux CI. While I noticed the tests were failing locally, the PR doesn't address the issue and I would like to focus on setting up infrastructure first.

I added badges for travis and appveyor to README. This URLs should be modified before or after merging.

Fixes #3

[r9y9]

Hi, @MattShannon, Could you take a look?

[r9y9]

bump

[MattShannon]

Ryuichi, thank you so much for helping get bandmat building in windows! That was incredibly helpful. As I mentioned in a previous comment, I actually use darcs and git is just a convenient wrapper so I can host on github, so I decided not to pull this PR as is, but as you can see I cribbed heavily from it.

Hope this helps close some of those downstream issues, and a thousand apologies that it took me so long to address this!

[r9y9]

@MattShannon Thank you very much for your response. I'm guessing you are working on fixing some problems now. If it's done, would you mind creating a new release?

[MattShannon]

Yep, bandmat 0.7 contains all the recent fixes. Tests are all green, though there's one test that's flakier than I'd like specifically on python3 64-bit windows.