Add a cli flag for running as an integration

[DamianZaremba]

Currently there is no way to enable the integration flag which the providers uses to filter out some actions.

It is possible to run the bot using an oauth app e.g. via github actions, however it will fail due to having no access to endpoints such as /user/emails.

With this PR supplying the --integration will enable restricted tokens to function as expected.

Fixed #411

[codecov[bot]]

Codecov Report

Merging #412 (81181e5) into master (17c2384) will decrease coverage by 0.25%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #412      +/-   ##
==========================================
- Coverage   94.24%   93.98%   -0.26%     
==========================================
  Files          11       11              
  Lines        1164     1114      -50     
==========================================
- Hits         1097     1047      -50     
  Misses         67       67              

Impacted Files	Coverage Δ
pyup/requirements.py	87.61% <0.00%> (-0.85%)	:arrow_down:
pyup/pullrequest.py	96.77% <0.00%> (-0.45%)	:arrow_down:
pyup/providers/gitlab.py	85.12% <0.00%> (-0.13%)	:arrow_down:
pyup/bot.py	97.83% <0.00%> (-0.05%)	:arrow_down:
pyup/config.py	98.92% <0.00%> (-0.02%)	:arrow_down:
pyup/providers/github.py	99.39% <0.00%> (-0.01%)	:arrow_down:
pyup/updates.py	100.00% <0.00%> (ø)

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[DamianZaremba]

Test failures will be fixed by https://github.com/pyupio/pyup/pull/410

[luischapis]

Tenkiu