Neomodel

* Back compat for exceptions module move - Robin Edwards
* Lower the required pytz version (328) - mprahl
* Add the "disconnect_all" and "replace" methods on relationship properties (327) - mprahl
* Add the "first" and "first_or_none" methods on the NodeSet class (325) - mprahl

* Code clean ups and documentation improvments - Frank Sachsenheim
* neomodel.properties.NormalClass is renamed to NormalizedClass
* Respect when db_property is set in install_labels and get_or_create - mprahl
* Use a clearer relationship name in the Relationships documentation - mprahl
* Improve relationship documentation - mprahl
* Ensure_connection only called when accessing the database, not when
constructing the transaction decorator - Robert Grant
* Test against newer neo4j releases - Frank Sachsenheim
* Fixes and simplifies pickling of DoesNotExist subclasses - Frank Sachsenheim
* Add NeomodelException and move exceptions to a module - Frank Sachsenheim
* Many documentation improvements - Frank Sachsenheim
* Add newline to is abstract warning 305 - Omer Yampel
* Refactors tests to use pytest as runner.- Frank Sachsenheim
* Remove support for Python 3.3 - Frank Sachsenheim
* Adds support for neo4j 3.3 - Frank Sachsenheim
* Updates .travis.yml in order to also test against various neo4j versions - Frank Sachsenheim
* Updates neo4j-driver dependency to 1.5.2 - Frank Sachsenheim
* Adds a script to tests against various platforms with Docker Compose - Frank Sachsenheim
* Fix service unavailable issue (281) - Warin Isvilanonda
* Add neomodel_remove_labels - Ivan Laković
* Test for model is None in Traversal.match() - pvanheus

* Upgrade pytz
* Remove use of START in match engine breaking neo4j 3.2

* Upgrade neo4j-driver to 1.2.1 251

* Return StructuredRel instance as opposed to None when no model supplied 248
* Fix get_or_create docs and incorrect call to rel_helper 249

* Add get_or_none to RelationshipManager 246
* Make sure relationship types are escaped in queries 188
* Fix bug causing unsaved node not to appear in deflate error msg
* Allow typed arrays in ArrayProperty 237
* Add save hooks to StructuredRel 242
* Add tests for UniqueIdProperty when used in batch or merge.
* Update documentation for batch operations
* Add all_relationships() method to RelationshipManager 239