MAR-148: Fixing linting errors:

- Do not compare against booleans when value is already boolean in
"when" conditions.
- Do not compare variables to empty strings in "when" conditions. This
change currently works only for complex variables (stuff can break
badly in case of simple variables in current default Ansible
configuration).

MAR-134: Fix Ansible warning about use of apt and with_items:

- The apt module can accept list of names already, and with_items is
considered to be deprecated in this regard (otherwise it would
end-up running one apt command per item).
- Changed multiple roles where apt was used together along with_items.

MAR-135: Switch to using run_handlers instead of handlers as variable:

- Updated all roles to now depend on run_handlers being set to True in
order to force execution of handlers.

MAR-132: Added support for Debian 9 (Stretch) to php_website role:

- Implemented the necessary changes related to differences between PHP
versions and related paths (PHP 5 vs PHP 7).
- Set the shell for application system account explicitly (workaround
for Debian bug 865762 in Stretch).
- Updated Molecule tests to cover Debian 9.
- Updated Molecule test preparation playbook to account for a number
of differences between Jessie and Stretch (mainly related to mailing
functionality).
- Use more specific host groups in tests.
- Renamed a couple of variables in test for sending out mails to make
it clearer what is being looked up as part of regex matching.
- Updated Molecule tests where certain paths depend on what Debian
release they are ran against.
- Split-up Jessie-specific tests into separate file.

MAR-129: Updated php_website role for Ansible 2.5.x and new Molecule:

- Include global linting configuration file in tests.
- Fixed linting issues.
- Fix deprecation warnings from Ansible (for apt module and
state=installed).
- Updated how the hosts are being referenced within tests.

MAR-114: Updated task syntax for web server/application roles:

- Updated web_server, php_website, and wsgi_website roles.
- Added and removed quoting where it makes sense.
- Switched to using expanded syntax (instead of one-liners).
- Updated ordering of arguments in task definitions.

MAR-114: Moved set_fact for wsgi_website and php_website roles:

- Moved set_fact for setting application admin, user, and home directory into
defaults/main.yml.
- Updated test playbook for wsgi_website to fixate the ptpython and dnspython
versions (including their dependencies).
- Updated tests for wsgi_website to use new fixated versions for ptpython,
dnspython, and their dependencies.

MAR-29: Implemented tests for php_website role:

- Install some additional tools for testing everything.
- Updated test playbook to change allowed extensions for running PHP scripts on
parameters-optional.
- Updated error page to use correct extension for parameters-optional test
instance.
- Expanded rewrite configuration slightly for parameters-optional.
- Install libmariadb-client-lgpl-dev-compat to test mysql_config symlink
creation.
- Deploy a number of PHP pages used for testing if pages are served correctly.
- Set file permissions on deployed PHP FPM pool configuraiton files.
- Use expanded syntax when deploying TLS keys/certificates in order to avoid
issues with TAB mangling.
- Fixed set-up of Strict-Transport-Security header when HTTPS enforcement is
disabled.
- Added a number of PHP and static test pages.
- Wrote tests covering full functionality of the role.

MAR-29: Added scaffolding for testing the php_website role:

- Added molecule configuration with a single instance.
- Added playbook that sets-up the test instances.
- Fixed issues related to incorrect mode syntax when deploying files (missing
leading zero).
- Added test data.
- Added dummy tests.