Fix calculation of VPC Network Interfaces limit

[TimGebert]

Summary

Fixes calculation for VPC Network Interface limit.

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[bergkampsliew]

looks like unit test needs fixing

[jantman]

@TimGebert

Thanks for the contribution! I wasn't aware of that bug in the NI limit calculation, and nobody else has noticed this yet either! It appears this was introduced in #379 and released in 6.1.0 about a month ago.

I'm going to be rather busy the next few days, so I might be able to get this fixed up and released while I'm working on other things, or else it might not be released until the weekend or early next week.

Yes, the unit test is definitely causing a build failure, because they're testing the previous logic. It should only take 3 changes to fix them. The unit test in question has a sample API response with "400" as the max-instances limit returned by the EC2 API, and expects the Network interfaces per Region limit to also be 400. Since it appears that the limit should really be multiplied by five but that was never done in the code, we'll want to expect the resulting Network interfaces per Region limit to be 2000 instead of 400... so the unit tests should be fixed by just changing the 400 on lines 385 and 386 of tests/services/test_vpc.py to 2000.

Thanks,
Jason

PS - Tim, this bug happened to be pretty obvious when looking at the changes in this PR. In the future, though, it would be helpful if you provided a more detailed overview of the problem for PRs that don't already have a matching issue containing all of the details requested in the issue template.

( cc @nadlerjessie on this PR, as I assume her employer is also using this code )

[codecov-io]

Codecov Report

Merging #394 into develop will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           develop   #394   +/-   ##
======================================
  Coverage      100%   100%           
======================================
  Files           30     30           
  Lines         2274   2274           
  Branches       338    338           
======================================
  Hits          2274   2274

Impacted Files	Coverage Δ
awslimitchecker/services/vpc.py	100% <100%> (ø)	⬆️

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[jantman]

I'm going to merge this now and try to get a release out today. I'll update when it's live on PyPI.

Thanks so much for the contribution, @TimGebert !!

[jantman]

This has been released as 6.1.4 and is live on PyPI.

Thank you so much!

[TimGebert]

Thanks @jantman for making it easy to get this in so easily, and constantly supporting the repo :)