With a new way to quickly build old git versions, this release fixes compatibility with Git 1.7.

Unfortunately, we had to increase our minimum supported version of Git to 1.7.2, in order to get git status --porcelain and orphan branches. Neither of these are that big of a deal-breaker, so in theory we could support some slightly older versions of git.

Full changelog below:

• fix git-rm compatibility with 1.7.2
• fix error adding submodule in test (#245)
• upgrade git requirement to 1.7.2
• fix git version tests to work on Travis
• add extra tests for git versions (#245)