Sync libraries & common files prior to freeze

* charm-helpers sync for classic charms
* charms.ceph sync for ceph charms
* rebuild for reactive charms
* sync tox.ini files as needed
* sync requirements.txt files to sync to standard

Change-Id: Ide5db8f0dd1658a36373c8ef481843836bf0f5c8

rebuild

@@ -2,4 +2,4 @@
 # when dependencies of the charm change,
 # but nothing in the charm needs to.
 # simply change the uuid to something new
-d994e036-d02c-11ea-b230-875ee8d654e2
+89499256-0016-11eb-9cee-f7176c5ee33c

requirements.txt

@@ -3,6 +3,7 @@
 # choices of *requirements.txt files for OpenStack Charms:
 #     https://github.com/openstack-charmers/release-tools
 #
+setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb244e9b27bc56750c44b7c85
 # Build requirements
 charm-tools>=2.4.4
 # importlib-resources 1.1.0 removed Python 3.5 support

test-requirements.txt

@@ -3,8 +3,9 @@
 # choices of *requirements.txt files for OpenStack Charms:
 #     https://github.com/openstack-charmers/release-tools
 #
+setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb244e9b27bc56750c44b7c85
 # Lint and unit test requirements
-flake8>=2.2.4,<=2.4.1
+flake8>=2.2.4
 stestr>=2.2.0
 requests>=2.18.4
 charms.reactive

tox.ini

@@ -94,4 +94,4 @@ commands = {posargs}
 
 [flake8]
 # E402 ignore necessary for path append before sys module import in actions
-ignore = E402,W504
+ignore = E402,W503,W504