Switch to develop branch for pypowervm

The master branch of nova-powervm should be paired to the 'develop'
branch of pypowervm.

Other stable branches (or release candidates) will point to version
levels that are published to PyPi (or to stable branches).

Change-Id: I963e20da759eeede6b1f115d15fdc276b3555538

tox.ini

@@ -11,7 +11,7 @@ setenv =
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
        -egit+https://github.com/openstack/nova#egg=nova
-       -egit+https://github.com/pypowervm/pypowervm#egg=pypowervm
+       -egit+https://github.com/pypowervm/pypowervm@develop#egg=pypowervm
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]