Add CI tests to drone

[dpakach]

Add drone.yml file and tests to drone
related to #242

[individual-it]

@ownclouders rebase

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@ac0556b). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #257   +/-   ##
=========================================
  Coverage          ?   67.27%           
  Complexity        ?       25           
=========================================
  Files             ?        4           
  Lines             ?      110           
  Branches          ?        0           
=========================================
  Hits              ?       74           
  Misses            ?       36           
  Partials          ?        0

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[phil-davis]

https://travis-ci.org/owncloud/files_texteditor/jobs/454907915

$ sh -c "if [ '$TC' = 'other' ]; then bash apps/$APP/tests/travis/start_php_unit_tests.sh; fi"
Running PHP unit tests
Could not read "phpunit.xml".
The command "sh -c "if [ '$TC' = 'other' ]; then bash apps/$APP/tests/travis/start_php_unit_tests.sh; fi"" exited with 1.

Moving stuff around broke the Travis script.
The easy way to fix that here is to remove the PHPunit jobs from the Travis YML! (since we are going to delete the whole of the Travis YML in the next PR anyway)
@dpakach

[phil-davis]

For drone, it will need the new QA tarball tonight. That will have the FilesPageCRUD methods that were added to core today.

changes have been addressed

review comments have been addressed

[phil-davis]

Looks good