Remove aiocache.Cache and alias support

[mikeoconnor0308]

What do these changes do?

Removes factory.py and associated factory tooling. Updates all the tests and documentation to reflect the changes.

Added a Migration guide to start documenting the changes for a v1 release.

Are there changes in behavior for the user?

• The aiocache.Cache class has been removed. Instead, use the specific cache class directly. For example, use aiocache.RedisCache instead of aiocache.Cache.REDIS.
• Caches should be fully instantiated when passed to decorators, rather than being instantiated with a factory function
• Cache aliases have been removed. Create an instance of the cache class directly instead.

Related issue number

Closes #677

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes

[Dreamsorcerer]

Thanks for looking at this. Seems to a very thorough PR.

[codecov]

Codecov Report

Attention: Patch coverage is 96.38554% with 3 lines in your changes missing coverage. Please review.

Project coverage is 99.64%. Comparing base (fe28c47) to head (7962e33).
Report is 114 commits behind head on master.

Files with missing lines	Patch %	Lines
tests/performance/server.py	70.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #948      +/-   ##
==========================================
- Coverage   99.76%   99.64%   -0.12%     
==========================================
  Files          36       33       -3     
  Lines        3794     3396     -398     
==========================================
- Hits         3785     3384     -401     
- Misses          9       12       +3     

Flag	Coverage Δ
unit	99.64% <96.38%> (-0.12%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
aiocache/__init__.py	100.00% <100.00%> (ø)
aiocache/decorators.py	100.00% <100.00%> (ø)
tests/acceptance/conftest.py	100.00% <100.00%> (ø)
tests/acceptance/test_decorators.py	100.00% <100.00%> (ø)
tests/performance/conftest.py	100.00% <100.00%> (ø)
tests/ut/conftest.py	100.00% <ø> (ø)
tests/ut/test_decorators.py	100.00% <100.00%> (ø)
tests/performance/server.py	92.85% <70.00%> (-7.15%)	⬇️

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ce1efa9...7962e33. Read the comment docs.

[mikeoconnor0308]

@Dreamsorcerer could you run the lint again?

[Dreamsorcerer]

Yep, sorry, missed the last change.

[mikeoconnor0308]

Apologies - some bad testing on my part, but also the linter on CI is different to make lint.

We should update the docs with precommit support and add a make format (but not in this PR).

Please run the lint again @Dreamsorcerer , it should be good now.

[Dreamsorcerer]

We should update the docs with precommit support and add a make format (but not in this PR).

Yeah, that'd be good. Also hoping to find some time to start some org-wide work on this stuff in future, so we can keep all repos in sync.