v0.3.0

• added inlet_concurrency for throttling inlets
• added cacert, params and headers support to HttpInlet
• added immediate_transfer mode to BasePlanner and links allowing to run transfer immediately upon starting
• Added atexit callback to BasePlanner which will attempt to gracefully shutdown upon unexpected exit.
• added force_transfer to BasePlanner
• added Processors, Groupers and Buffers
• bumped aiohttp 3.6.2 to 3.7.4
• removed logging.CRITICAL switches from tests