Docker compose redis worker

[nhoening]

Closes #418

Also adds more documentation and lets us add schedules as a job in the CLI.

[coveralls]

Pull Request Test Coverage Report for Build 2679470627

• 11 of 51 (21.57%) changed or added relevant lines in 3 files are covered.
• 252 unchanged lines in 13 files lost coverage.
• Overall coverage decreased (-0.9%) to 67.485%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
flexmeasures/utils/config_utils.py	0	1	0.0%
flexmeasures/cli/data_add.py	2	14	14.29%
flexmeasures/cli/jobs.py	9	36	25.0%

Files with Coverage Reduction	New Missed Lines	%
flexmeasures/data/models/data_sources.py	1	56.16%
flexmeasures/data/schemas/utils.py	1	81.25%
flexmeasures/utils/config_utils.py	1	31.3%
flexmeasures/cli/jobs.py	2	27.66%
flexmeasures/api/v3_0/assets.py	3	96.15%
flexmeasures/data/services/sensors.py	7	26.09%
flexmeasures/api/v3_0/sensors.py	18	70.1%
flexmeasures/api/dev/sensors.py	20	61.64%
flexmeasures/data/models/charts/defaults.py	21	52.04%
flexmeasures/data/models/charts/belief_charts.py	27	13.33%

Totals
Change from base Build 2638960995:	-0.9%
Covered Lines:	7150
Relevant Lines:	10025

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💛 - Coveralls

[Flix6x]

Nice to have the asynchronous stuff dockerized, too now. Here are my initial comments. I still need to test.

[Flix6x]

My only remaining comment is about showing and clearing the failed queue. If this is holding the PR back, feel free to revert the applicable commits and to open a separate PR for that.