Refactored tox requirements for different Ansible releases

Sorted pip requirements file to improve readability.

Moved pip requirements for tests into tests subdirectory and dropped
'pip-' prefix to shorten filenames and conform with common naming
scheme for pip requirements files.

Added constrains on OpenStack SDK 1.*.* to job ansible-collections-\
openstack-functional-devstack-releases on master branch because only
stable/1.0.0 branch is compatible to the OpenStack SDK 0.*.* series.

Changed job ansible-collections-openstack-functional-devstack-releases
on master branch to non-voting because OpenStack SDK 1.*.* has not
been released to PyPI yet, so tests on master branch are expected to
fail once we introduce breaking changes from stable/1.0.0 branch.

Change-Id: I6b6bb8c6900f7c8341bbf3f9a24999fbf693ba4b

tests/constraints-openstacksdk-1.x.x.txt

@@ -0,0 +1 @@
+openstacksdk>=1.0.0

tests/requirements-ansible-2.11.txt

@@ -0,0 +1,11 @@
+ansible-core>=2.11.0,<2.12.0
+flake8
+galaxy-importer
+openstacksdk
+pycodestyle
+pylint
+rstcheck
+ruamel.yaml
+tox
+voluptuous
+yamllint

tests/requirements-ansible-2.12.txt

@@ -0,0 +1,11 @@
+ansible-core>=2.12.0,<2.13.0
+flake8
+galaxy-importer
+openstacksdk
+pycodestyle
+pylint
+rstcheck
+ruamel.yaml
+tox
+voluptuous
+yamllint

tests/requirements-ansible-2.9.txt

@@ -0,0 +1,13 @@
+ansible>=2.9.0,<2.10.0
+flake8
+# galaxy-importer 0.3.2 moved from ansible 2.9 to ansible-core 2.11
+# Ref.: https://github.com/ansible/galaxy-importer/commit/98933547831922c45243f39d85eefe150b55fc36
+galaxy-importer==0.3.1
+openstacksdk
+pycodestyle
+pylint
+rstcheck
+ruamel.yaml
+tox
+voluptuous
+yamllint

tests/requirements.txt

@@ -0,0 +1,11 @@
+ansible-core
+flake8
+galaxy-importer
+openstacksdk
+pycodestyle
+pylint
+rstcheck
+ruamel.yaml
+tox
+voluptuous
+yamllint