[test] fix and clean basic tests to add complex one (such as remove message)

[misstick]

wait for these merge before merge this one:

• [fix] tests https://github.com/cozy/cozy-emails/pull/874,
• [test] routerStore https://github.com/cozy/cozy-emails/pull/870,
• [feature] remove message https://github.com/cozy/cozy-emails/pull/873,
• [config] js files https://github.com/cozy/cozy-emails/pull/879

  TODO

• [x] add improvement asked here: https://github.com/cozy/cozy-emails/pull/870
• [x] fix MessageStoreTests,
• [x] fix AccountStoreTests,
• [ ] fix ContactStoreTests,
• [ ] fix RouterStoreTests,
• [x] fix consistency issues: add fixture modules instead of using a local objet,
• [x] fix test workflow: reset context after each.

[frankrousseau]

Can you make sure that the linter returns no error?

[m4dz]

@frankrousseau linters are a complex problem IMHO: never same linters nor version, sparse configs… If I can, I suggest we let @misstick finished the objective of this PR, and I'll open another one to address specific linters issues / config :)

[frankrousseau]

OK to finish this PR without linting. But the linter is already configured. So, there is not much work to do about it. It just needs to be added to Travis.

[misstick]

@poupotte : I've not finished the 1rst scope, but:

• RouterStoreTests will take some days to be completed (maybe 3-4),
• ContactStoreTests are small test but i would imply:
  • adding tests on messagesStore to handle to, cc, from etc. fields,
  • add fixtures/contact.js to get these data from several spec files,
  • then clean contact tests.
• and I think that requestsStore should be improved before adding tests on this Store so that it will take few time to add tests.

@m4dz: you can review this PR, it is "complete" :)

[aenario]

If possible, avoid using new Date() in tests as it is not pure and cause intermittence in my tests.