Revert "Limit max requests version to 1.2.3"

This reverts commit 4d8700093e3b44e8cac286ab13e5ef670b7db7dc.
Use ArchLinux vagrant box from Vagrant Cloud
Add Ubuntu Trusty vm for testing
Add python-setuptools to runtime dependencies
Install pkgbuild-introspection during provisioning

It includes mkaurball that is needed to produce "source package" for AUR.