Concert 0.31.0

Features

• it is possible to use await statements in concert sessions outside of async def functions
• AsyncObject allows us to have async constructors async def __ainit__,which is very useful when we need to use async code in constructors, e.g. setting a parameter on a device
• Experiments were greatly extended by classes which can be customized and run at beam lines without many more changes
• Monochromators were enhanced
• Experiment director was introduced to take care of high-throughput measurements
• Experiments can write metadata to json
• Parameter limits getters and setters are coroutine functions
• Add ElementSelector device for having discrete choices
• ascan allows one to include the stop value in the scan
• walkers have create_writer method for convenience
• walkers can be used in async with statements for safe access from multiple
  concurrent coroutines
• concert.coroutines.sinks.Accumulate allows non-re-setting behavior between runs
• concert.processes.common.align_rotation_axis allows multiple frame consumers
• concert.devices.cameras.uca.Camera gets state from the libuca object

API breaks

• Parameterizable inherits from AsyncObject which needs an __ainit__ constructor, so every sub-class must change its __init__ to async def __ainit__.
• run_in_loop_thread_blocking is gone in favour of using one event loop and
  __ainit__ constructors

Notes

• we replaced Travis by CircleCI

Pull Requests

#485 from ufo-kit/circleci-project-setup
#483 from ufo-kit/new-metadata
#464 from ufo-kit/monochromator-enhancement
#459 from ufo-kit/experiment-director
#409 from ufo-kit/fix-uca-state
#467 from ufo-kit/grating-inteferometry-experiment
#478 from ufo-kit/hercules
#473 from ufo-kit/walkers
#471 from ufo-kit/ascan-include-last
#470 from ufo-kit/elementselector
#466 from ufo-kit/fix-tango-loop
#458 from ufo-kit/new-experiments
#461 from ufo-kit/async-limits