Test invalid endpoint_url

[jakob-keller]

Description of Change

Test invalid endpoint_url

Assumptions

None

Checklist for All Submissions

• I have added change info to CHANGES.rst
• If this is resolving an issue (needed so future developers can determine if change is still necessary and under what conditions) (can be provided via link to issue with these details):
  • Detailed description of issue
  • Alternative methods considered (if any)
  • How issue is being resolved
  • How issue can be reproduced
• If this is providing a new feature (can be provided via link to issue with these details):
  • Detailed description of new feature
  • Why needed
  • Alternatives methods considered (if any)

Checklist when updating botocore and/or aiohttp versions

• I have read and followed CONTRIBUTING.rst
• I have updated test_patches.py where/if appropriate (also check if no changes necessary)
• I have ensured that the awscli/boto3 versions match the updated botocore version

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 86.97%. Comparing base (33c6293) to head (6bdbf2f).
Report is 2 commits behind head on master.

Files	Patch %	Lines
tests/test_endpoint.py	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1151      +/-   ##
==========================================
+ Coverage   86.95%   86.97%   +0.01%     
==========================================
  Files          63       64       +1     
  Lines        5963     5971       +8     
==========================================
+ Hits         5185     5193       +8     
  Misses        778      778              

Flag	Coverage Δ
unittests	86.97% <87.50%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.