Overhaul ansible-test sanity implementation. (#22177)

- Tests are run to completion instead of stopping on first failure.
- Test results are now parsed instead of passing through to the console.
- Test results can be saved in junit xml format.
- Test results will show up on the Shippable "Tests" result tab.
- Added an experimental --lint option for easier integration with other tools.
- Code smell tests are now usable with the --list-tests, --test and --skip-test options.
- Code split out from executor.py into sanity.py.
- Rename download-logs to download.py and add support for test and coverage results.
- Miscellaneous improvements.

test/sanity/code-smell/no-iterkeys.sh

@@ -3,7 +3,9 @@
 ITERKEYS_USERS=$(grep -r -I iterkeys . \
     --exclude-dir .git \
     --exclude-dir .tox \
+    --exclude-dir .idea \
     --exclude-dir docsite \
+    --exclude-dir results \
     | grep -v \
     -e lib/ansible/compat/six/_six.py \
     -e lib/ansible/module_utils/six.py \