test: skip all customization tests, as they rely on each other

[dpopp07]

The tests were failing because the customization tests relied on each other (deleteWord needed addWord to add words to delete). Since the customization tests take the longest, I decided to tag the whole block with @slow.

I also tagged the websockets tests from environment credentials as I noticed they were taking up to 8 seconds each.

The tests should pass now.

[codecov-io]

Codecov Report

Merging #752 into master will decrease coverage by 0.79%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master     #752     +/-   ##
=========================================
- Coverage   83.98%   83.18%   -0.8%     
=========================================
  Files          35       35             
  Lines        4390     4390             
  Branches      553      553             
=========================================
- Hits         3687     3652     -35     
- Misses        324      357     +33     
- Partials      379      381      +2

Impacted Files	Coverage Δ
speech-to-text/v1.ts	67.25% <0%> (-7.53%)	⬇️
lib/recognize-stream.ts	53.98% <0%> (-7.37%)	⬇️
iam-token-manager/v1.ts	83.33% <0%> (-4.17%)	⬇️
lib/base_service.ts	82.72% <0%> (-2.73%)	⬇️
lib/requestwrapper.ts	89.69% <0%> (-1.04%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1576814...eb89087. Read the comment docs.

[watson-github-bot]

🎉 This PR is included in version 3.7.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀