Update layer wheelhouse with common dependencies

Add empty series list to metadata.yaml to get around charm-tools
now mandating a series list to be present.

This list will always be overridden by charms but building the
layer is part of our gate and we need to unblock it.

Update tox basepython, the build will no longer succeed in the gate
with py27.

Change-Id: If81441d5fb0ed3b8819c4a2814dc20c5e47a8eff

metadata.yaml

@@ -5,3 +5,4 @@ description: |
  The Base Layer for OpenStack reactive charms
 tags:
   - openstack
+series: []

requirements.txt

@@ -1,5 +1,4 @@
 # Requirements to build the layer
 charm-tools
-ruamel.yaml==0.10.12
 simplejson
 flake8

tox.ini

@@ -4,7 +4,7 @@ envlist = pep8
 toxworkdir = /tmp/tox
 
 [testenv]
-basepython = python2.7
+basepython = python3
 setenv = VIRTUAL_ENV={envdir}
          PYTHONHASHSEED=0
          TERM=linux
@@ -29,7 +29,6 @@ commands =
   /bin/ln -s {envdir}/tmp/build {toxinidir}/build
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:py27]

wheelhouse.txt

@@ -1,3 +1,8 @@
+# charmhelpers.contrib.openstack.cert_utils charms with certificates relation
+dnspython
+# charmhelpers.contrib.network all
 netifaces>=0.10.4
+# charmhelpers.contrib.openstack.context all
+psutil
 # charms_openstack - pull from github until first release
 git+https://github.com/openstack/charms.openstack.git#egg=charms.openstack