Complete Sat6 integration

Various fixes to get sat-6 integration working.

* inventory_import.py - the inventory script is called foreman.py
* tasks.py - be sure to call `add_section()` before using it
* defaults.py - Add various SATELLITE6_* enablement variables

Relates #3119

awx/main/management/commands/inventory_import.py

@@ -481,6 +481,7 @@ def load_inventory_source(source, all_group=None, group_filter_re=None,
     # Sanity check: We sanitize these module names for our API but Ansible proper doesn't follow
     # good naming conventions
     source = source.replace('azure.py', 'windows_azure.py')
+    source = source.replace('satellite6.py', 'foreman.py')
     logger.debug('Analyzing type of source: %s', source)
     original_all_group = all_group
     if not os.path.exists(source):

awx/main/tasks.py

@@ -1299,9 +1299,11 @@ class RunInventoryUpdate(BaseTask):
                 cp.set(section, 'password', decrypt_field(credential, 'password'))
 
             section = 'ansible'
+            cp.add_section(section)
             cp.set(section, 'group_patterns', '["{app}-{tier}-{color}", "{app}-{color}", "{app}", "{tier}"]')
 
             section = 'cache'
+            cp.add_section(section)
             cp.set(section, 'path', '/tmp')
             cp.set(section, 'max_age', '0')