Add utils.is_integer utility
Test stubs for DummyKvResource
Implement DummyKvResource
Allow DummyKvStore to be initialised with data
Add DummyKvResource to DummyApi
Update AppTester setup tasks: setup.kv(fn) now takes the DummyKvResource instance as an arg
Update the rest of the world to work with the new DummyKvResource
Add DummyKvResource to DummyApi docs
Fix bad test description for utils.is_integer: .exists -> .is_integer
Merge branch 'develop' into feature/issue-121-add-a-new-dummy-kv-resource

Conflicts:
	docs/dummy.rst
	lib/dummy/api.js
	lib/test_utils.js
	lib/tester/setups.js
Merge branch 'feature/issue-121-add-a-new-dummy-kv-resource' into develop