pep8/pyflakes fixes. (Hodgestar)
ContactNotFoundError should subclass ContactError
Refactoring to prevent the non-settable contact fields from being set; review fixes
Merge branch 'develop' into feature/issue-220-contactsresource-contact-model-changes-should-always-be-saved
Merge branch 'feature/issue-220-contactsresource-contact-model-changes-should-always-be-saved' into develop
Merge branch 'develop' into feature/issue-216-contactsresource-needs-docstrings-and-commenting
Merge branch 'feature/issue-216-contactsresource-needs-docstrings-and-commenting' of github.com:praekelt/vumi-go into feature/issue-216-contactsresource-needs-docstrings-and-commenting