Merge tag '0.5.5' into develop

Introduced automatic reconnection after 65 seconds of no data or ticks. Solves 'silent disconnect' issue
Mock out _read_chunk to fix user exceptions tests
Remove tests for HTTP exceptions

There were some tests for the library handling HTTP exceptions
thrown during `read_stream`, these can no longer be thrown as
the library now uses raw sockets.
Fix test fixtures broken by the OUTPUT_PARAMS_PREFIX change in 361f7791ba2
Fix broken StreamConsumer._get_url() for multiple hashes
Bump version
fixed automatic reconnection after 65s timeout on receiving TICK
Update README.md
Merge pull request #32 from datasift/feature/reconnect

fixed automatic reconnection after 65s timeout on receiving TICK
Merge pull request #29 from alexjg/fix-tests

Fix tests and broken multi streaming
Bumped version to v.0.5.6
Merge branch 'release/0.5.6'