Add user methods: update user data, and get email

[llunaCreixent]

• Create methods: updateUser, and getEmail
• Create tests
• Use testing version of dockers
• Add getEmail method
• Set dockers back to main in GHActions workflow file, after merging

You can test with the circles-docker branch update-users-feature.

Closes #123

[llunaCreixent]

Tests pass locally for me

[llunaCreixent]

@mikozet , I've published a testing version (@circles/core@2.12.0-pre-4140b0a), so you can import it to test myxogastria.
Remember to use the new branches for the docker repo, and install the new core package in the myxo repo.

[mikozet]

Hi @llunaCreixent
I run tests few times and it looks like they are failing at one point:

[llunaCreixent]

Hi @llunaCreixent
I run tests few times and it looks like they are failing at one point:

Then we have to reimplement this test somehow

[JacqueGM]

LGTM when version and branches have been updated properly ^^