PR: Add tests for external plugins using spyder-boilerplate

[ccordoba12]

Description of Changes

• Install spyder-boilerplate on CIs and run tests related to it only there.
• Skip some flaky tests to improve running time in CIs.
• Use spyder-boilerplate to test functionality related to external plugins.
• Don't use pkg_resources to register completion provider entrypoints when running on CIs. That help us to test if they work when the package is installed.

Affirmation

By submitting this Pull Request or typing my (user)name below,
I affirm the Developer Certificate of Origin
with respect to all commits and content included in this PR,
and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: @ccordoba12

[pep8speaks]

Hello @ccordoba12! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file spyder/app/tests/spyder-boilerplate/setup.py:

Line 31:80: E501 line too long (85 > 79 characters)

• In the file spyder/plugins/completion/tests/test_configdialog.py:

Line 42:5: E303 too many blank lines (2)

Comment last updated at 2021-08-07 21:28:43 UTC