Update tox.ini files from release-tools gold copy

All OpenStack Charms now contain identical tox.ini files,
not to be modified or made unique within each charm repo.

This is to ensure consistency across charm repos in tox
target naming, approach and purpose, also giving the
charm dev and test experience additional consistency.

Also create empty dirs with .keep files where necessary.
Some classic charms have actions and/or lib dirs, and some
do not. In all classic charms, flake will now check those
dirs to ensure lint coverage of existing or future content.

Change-Id: I736a5f33bcf37eee2b90cb266bb7d9ad85166a58

tox.ini

@@ -1,3 +1,6 @@
+# Classic charm: ./tox.ini
+# This file is managed centrally by release-tools and should not be modified
+# within individual charm repos.
 [tox]
 envlist = pep8,py27
 skipsdist = True
@@ -5,11 +8,13 @@ skipsdist = True
 [testenv]
 setenv = VIRTUAL_ENV={envdir}
          PYTHONHASHSEED=0
+         CHARM_DIR={envdir}
          AMULET_SETUP_TIMEOUT=2700
-passenv = HOME TERM AMULET_*
 install_command =
   pip install --allow-unverified python-apt {opts} {packages}
 commands = ostestr {posargs}
+whitelist_externals = juju
+passenv = HOME TERM AMULET_*
 
 [testenv:py27]
 basepython = python2.7
@@ -20,9 +25,12 @@ deps = -r{toxinidir}/requirements.txt
 basepython = python2.7
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-commands = flake8 {posargs} hooks unit_tests tests actions
+commands = flake8 {posargs} hooks unit_tests tests actions lib
            charm-proof
 
+[testenv:venv]
+commands = {posargs}
+
 [testenv:func27-noop]
 # DRY RUN - For Debug
 basepython = python2.7
@@ -49,6 +57,15 @@ deps = -r{toxinidir}/requirements.txt
 commands =
     bundletester -vl DEBUG -r json -o func-results.json gate-basic-xenial-mitaka --no-destroy
 
+[testenv:func27-dfs]
+# Charm Functional Test
+# Run all deploy-from-source tests which are +x (may not always pass!)
+basepython = python2.7
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/test-requirements.txt
+commands =
+    bundletester -vl DEBUG -r json -o func-results.json --test-pattern "dfs-*" --no-destroy
+
 [testenv:func27-dev]
 # Charm Functional Test
 # Run all development test targets which are +x (may not always pass!)
@@ -58,9 +75,6 @@ deps = -r{toxinidir}/requirements.txt
 commands =
     bundletester -vl DEBUG -r json -o func-results.json --test-pattern "dev-*" --no-destroy
 
-[testenv:venv]
-commands = {posargs}
-
 [flake8]
 ignore = E402,E226
-exclude = hooks/charmhelpers
+exclude = */charmhelpers