This fixes following error when building from source distribution
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/private/var/folders/ch/72dmd7t14cq6nr3gp86qync40000gp/T/pip-build-jncV6o/keen/setup.py", line 29, in <module>
version_file = open(os.path.join('.', 'VERSION'))
IOError: [Errno 2] No such file or directory: './VERSION'
This fixes following error when building from source distribution