Start refactoring of the trigger system:

- Move each trigger handler into its own file
- Add dictionary helper classes for easier reading and writing of dict-based data
- Extract the web hook payload -> internal representation building for each trigger system
- Add tests for this transformation
- Remove support for Github archived-based building

requirements.txt

@@ -32,6 +32,7 @@ iso8601==0.1.10
 itsdangerous==0.24
 Jinja2==2.7.3
 jsonschema==2.5.1
+jsonpath-rw==1.4.0
 Mako==1.0.1
 marisa-trie==0.7.2
 MarkupSafe==0.23