added support for file: and hdfs: schemes
reader and writer are not internally consistent - removing timestamp read from wrong field for testing
"scheme": "file" works :)
will submit another PR for STREAMS-167 which will allow timestamps and metadata reading from a previously written hdfs stream.
added test cases as discussed:
https://github.com/apache/incubator-streams/pull/85
Merge commit 'dc68334029dba329b0efa2a60d44820d4b9ed907'