SingleRequestTransformer working in tests
Merge branch 'master' into short-lived-streams

Conflicts:
	test/all_tests.dart
Move transformers_test into streamy_test.
SingleRequestTransformer -> OneShotRequestTransformer
Merge pull request #11 from alxhub/short-lived-streams

SingleRequestTransformer filters a Streamy stream and only returns results from the first initial request/response cycle, then closes the stream.