Improve HTTP and ZeroMQ adapters

[callumforrester]

Closes #111 and #15

Changes:

• Add synchronised start/stop mechanism to HTTP adapter
• Write suite of tests using this mechanism
• Make HTTP adapter support interrupts (it did not appear to already)
• Remove include_json parameter from HTTP endpoints as aiohttp can work that out for itself
• Create new ZeroMQ adapter specifically for pushing. The previous one had issues and also implemented more functionality than was needed. Multiple ZMQ adapters for the different ZMQ socket modes (PUSH, PUBLISH, DEALER etc.) seems like a better way to go.
• Synchronize ZeroMQ socket binding with a lock to avoid conflicts
• Write suite of tests for ZeroMQ push adapter

[codecov[bot]]

Codecov Report

Merging #137 (3c291ff) into master (6483aac) will increase coverage by 1.29%. The diff coverage is 94.87%.

@@            Coverage Diff             @@
##           master     #137      +/-   ##
==========================================
+ Coverage   92.48%   93.78%   +1.29%     
==========================================
  Files          45       45              
  Lines        1225     1271      +46     
==========================================
+ Hits         1133     1192      +59     
+ Misses         92       79      -13     

Impacted Files	Coverage Δ
src/tickit/adapters/zeromq/push_adapter.py	91.04% <91.04%> (ø)
src/tickit/adapters/httpadapter.py	100.00% <100.00%> (+48.57%)	:arrow_up:
...t/adapters/interpreters/endpoints/http_endpoint.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

[callumforrester]

@abbiemery have added some entries in the examples directory.