Cleanup python requirements

there are a number of requirements listed in requirements.txt that can
be dropped or moved around, especially since bifrost begins to support
installing/operating ironic on a remote host:

- six - not used directly. Is listed as dependency for os_ironic_facts
  module, but so is shade which requires it anyway.

- Jinja2 - not used directly, is a dependency for Ansible

- Babel - not used directly as no strings use i18n in bifrost inventory,
  and even when they begin to, this should be done through oslo.i18n instead.
  It is also pulled in as oslo.log->oslo.i18n->Babel dependency anyway.

- PyMySQL - not used by bifrost inventory itself, is installed as part of
  bifrost-ironic-install role.

- pycrypto - not used by bifrost itself, but will be installed as Ansible
  dependency

- PyYAML - although used by bifrost inventory, in real usage we
  should better rely on Ansible's dependency on PyYAML for that and use
  whatever version Ansible developers declare as required.
  Moved to test-requirements for running tests without installing
  Ansible.

Change-Id: I8021ec10f82b17590dd86780da6e27589fdea1ba

requirements.txt

@@ -1,12 +1,6 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-PyYAML>=3.10.0 # MIT
-Jinja2!=2.9.0,!=2.9.1,!=2.9.2,!=2.9.3,!=2.9.4,>=2.8 # BSD License (3 clause)
 pbr>=1.8 # Apache-2.0
-Babel>=2.3.4 # BSD
 oslo.config!=3.18.0,>=3.14.0 # Apache-2.0
 oslo.log>=3.11.0 # Apache-2.0
-six>=1.9.0 # MIT
-PyMySQL>=0.7.6 # MIT License
-pycrypto>=2.6 # Public Domain

test-requirements.txt

@@ -13,3 +13,4 @@ oslotest>=1.10.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=1.4.0 # MIT
+PyYAML>=3.10.0 # MIT