Allow to configure advanced SSL options

This patch allows to configure advanced ssl options like:
  ssl_crl
  ssl_dhparam
  ssl_stapling_responder
  ssl_stapling_verify
  ssl_verify_client
  ...and others
The whole list of options may be found in nginx/files/_ssl.conf
Theirs description:
http://nginx.org/en/docs/http/ngx_http_ssl_module.html

The 'mode' trigger is deprecated and will be removed in future together
with _ssl_normal.conf and _ssl_secure.conf. All options should be
set from reclass directly.

The following options changed theirs types (for backward compatibility
new type will be applied only when mode is set to != secure)
ssl_ciphers, ssl_ecdh_curve - was string, become list
Please read README for more details

Added kitchen tests

Related-PROD: PROD-19154

Change-Id: I03e735af6ff6794610e00d745d5a7054fb02186a
diff --git a/.travis.yml b/.travis.yml
index 1bdd382..ff193ee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,6 +24,7 @@
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=redirect
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=static
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=stats
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=proxy-with-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=horizon-no-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=horizon-with-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=proxy
@@ -31,6 +32,7 @@
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=redirect
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=static
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=stats
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=proxy-with-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=horizon-no-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=horizon-with-ssl
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=proxy
@@ -38,6 +40,7 @@
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=redirect
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=static
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=stats
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=proxy-with-ssl
     # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=horizon-no-ssl
     # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=horizon-with-ssl
     # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=proxy