Install Python 3.3 from the Deadsnakes PPA. As this doesn't have pip,
install it manually into ~/.local.
~/.local/bin is apparently in Travis's default PATH, meaning "pip"
doesn't refer to Python 2's pip anymore, but to the manually
installed Python 3 version. Updated the scripts to use version-
suffixed executable names (e.g. pip2.7).
Set CC=cc to use system's default compiler when installing Python
modules, as gcc on OS X had a problem with compiling one of the
dependencies of the Neovim Python module.
Florian Walch
a3399f9a63