Fix badge height.
All tests passing in Windows.
Update the appveyor configuration to run tests and show build failures.
Try coercing node-gyp to use VS2013.
Ensure rimraf exists for installation.
Improve the installation flow.
Windows Support.

This commit finally introduces passing Windows support for both Win32
and Win64 operating systems.

Note: If you are installing on a modern Windows operating system such as
Windows Server 2012 or Windows 8.1 and are using the latest Visual
Studio, you may have to toggle the installation from the standard

  npm install

to instead use the following build flag:

  npm install --msvs_version=2013

All tests should be passing, per the CI.
Version bump to 0.1.2.
Updates to README.
Fix erroneous OS detection for installation in OS X.
Version bump to 0.1.3, following hotfix.
Only accept CMake 2.8.
Enable promises over the entire Nodegit API.
Saving point for promises. -- Remove this commit.