Switch the 'incoming-phone-number' topic to 'phone-numbers'

[childish-sambino]

Fixes

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I updated my branch with the master branch.
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation about the functionality in the appropriate .md file
• I have added in line documentation to the code I modified

Contributing to Twilio

All third party contributors acknowledge that any contributions they provide will be made under the same open source license that the open source project is provided under.

Short description of what this PR does:

• Switch the 'incoming-phone-number' topic to 'phone-numbers'

If you have questions, please file a support ticket, or create a Github Issue in this repository.

[codecov]

Codecov Report

Merging #36 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #36      +/-   ##
==========================================
- Coverage   98.42%   98.41%   -0.01%     
==========================================
  Files          22       22              
  Lines         570      568       -2     
==========================================
- Hits          561      559       -2     
  Misses          9        9

Impacted Files	Coverage Δ
src/commands/phone-numbers/update.js	100% <ø> (ø)
src/commands/phone-numbers/list.js	100% <ø> (ø)

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[thinkingserious]

It's strange that code coverage went down. I think it's OK.

[childish-sambino]

@thinkingserious It's because 2 tested lines were removed (the aliasing).