add a request ID for all logs generated during request handling

[edaniszewski]

This PR:

• adds a request ID within the context of a request being processed, so all logs generated for the request will have the request ID associated with them, making it easier to tie log events to specific requests. this can be expanded upon in the future.

Example:

timestamp='2020-01-30T13:29:31.096917Z' logger='synse_server.api.http' level='debug' event='processing request' request_id='wfYy33jjFexsVFRbLjV7zj' method='GET' ip='172.18.0.1' path='/v3/plugin'
timestamp='2020-01-30T13:29:31.097165Z' logger='synse_server.cmd.plugin' level='info' event='issuing command' request_id='wfYy33jjFexsVFRbLjV7zj' command='PLUGINS'
timestamp='2020-01-30T13:29:31.097775Z' logger='sanic.access' level='info' event='' extra={'status': 200, 'byte': 236, 'host': '172.18.0.1:52010', 'request': 'GET http://localhost:5000/v3/plugin'}
timestamp='2020-01-30T13:29:35.008360Z' logger='synse_server.api.http' level='debug' event='processing request' request_id='nDs6XFxtGqR8ZsNCykj4MV' method='GET' ip='172.18.0.1' path='/v3/plugin'
timestamp='2020-01-30T13:29:35.008599Z' logger='synse_server.cmd.plugin' level='info' event='issuing command' request_id='nDs6XFxtGqR8ZsNCykj4MV' command='PLUGINS'
timestamp='2020-01-30T13:29:35.008946Z' logger='sanic.access' level='info' event='' extra={'status': 200, 'byte': 236, 'host': '172.18.0.1:52014', 'request': 'GET http://localhost:5000/v3/plugin'}
timestamp='2020-01-30T13:29:36.200119Z' logger='synse_server.api.http' level='debug' event='processing request' request_id='gGRM5xP8HZBP2cB9wUyBFL' method='GET' ip='172.18.0.1' path='/v3/plugin'
timestamp='2020-01-30T13:29:36.200417Z' logger='synse_server.cmd.plugin' level='info' event='issuing command' request_id='gGRM5xP8HZBP2cB9wUyBFL' command='PLUGINS'
timestamp='2020-01-30T13:29:36.200786Z' logger='sanic.access' level='info' event='' extra={'status': 200, 'byte': 236, 'host': '172.18.0.1:52018', 'request': 'GET http://localhost:5000/v3/plugin'}
timestamp='2020-01-30T13:30:04.919274Z' logger='synse_server.api.http' level='debug' event='processing request' request_id='jx5568Jw5kyjv4YaZaKUYM' method='GET' ip='127.0.0.1' path='/test'
timestamp='2020-01-30T13:30:04.919471Z' logger='synse_server.cmd.test' level='info' event='issuing command' request_id='jx5568Jw5kyjv4YaZaKUYM' command='TEST'
timestamp='2020-01-30T13:30:04.920018Z' logger='sanic.access' level='info' event='' extra={'status': 200, 'byte': 58, 'host': '127.0.0.1:49230', 'request': 'GET http://localhost:5000/test'}
timestamp='2020-01-30T13:31:04.979576Z' logger='synse_server.api.http' level='debug' event='processing request' request_id='NzR6DLN6oMhjr6TJ4njNPZ' method='GET' ip='127.0.0.1' path='/test'
timestamp='2020-01-30T13:31:04.979752Z' logger='synse_server.cmd.test' level='info' event='issuing command' request_id='NzR6DLN6oMhjr6TJ4njNPZ' command='TEST'
timestamp='2020-01-30T13:31:04.980202Z' logger='sanic.access' level='info' event='' extra={'status': 200, 'byte': 58, 'host': '127.0.0.1:49232', 'request': 'GET http://localhost:5000/test'}
timestamp='2020-01-30T13:31:05.784241Z' logger='synse_server.tasks' level='info' event='task: refreshing plugins' task='periodic plugin refresh' interval=120
timestamp='2020-01-30T13:31:05.784540Z' logger='synse_server.plugin' level='debug' event='refreshing plugin manager'
timestamp='2020-01-30T13:31:05.784767Z' logger='synse_server.plugin' level='info' event='loading plugins from configuration'

Note the request_id field in some of the messages.