Don't run danger if DANGER_GITHUB_API_TOKEN is not set

[shilman]

Issue: #1275

What I did

Don't run danger if DANGER_GITHUB_API_TOKEN is not set

How to test

• Danger should not break the build on this PR
• Danger should not be run on Fix typo in contributing guide #1273 after we marge

[orta]

This means anyone making a PR from a fork won't have danger run for them, it's your call if that's what you're looking for. However, I'd recommend making the bot have no access and making the token non-secret on CI

[codecov]

Codecov Report

Merging #1276 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1276   +/-   ##
=======================================
  Coverage   13.73%   13.73%           
=======================================
  Files         207      207           
  Lines        4638     4638           
  Branches      510      519    +9     
=======================================
  Hits          637      637           
- Misses       3550     3551    +1     
+ Partials      451      450    -1

Impacted Files	Coverage Δ
.../src/manager/containers/CommentsPanel/dataStore.js	34.78% <0%> (ø)	⬆️
addons/info/src/components/markdown/htags.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/ui/containers/left_panel.js	20% <0%> (ø)	⬆️
lib/ui/src/modules/ui/containers/layout.js	12.5% <0%> (ø)	⬆️
addons/knobs/src/components/types/Boolean.js	11.62% <0%> (ø)	⬆️
...rc/modules/ui/components/left_panel/text_filter.js	33.33% <0%> (ø)	⬆️
.../ui/src/modules/ui/components/layout/dimensions.js	15.62% <0%> (ø)	⬆️
app/react/src/client/preview/init.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/ui/configs/init_panels.js	25% <0%> (ø)	⬆️
addons/knobs/src/components/PropField.js	10.86% <0%> (ø)	⬆️
... and 22 more

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[orta]

I had a think about this, you could create two tokens on your CI a private DANGER_GITHUB_API_TOKEN, which has access to the status API, and a DANGER_GITHUB_API_TOKEN_OPEN which has no access, that you switch at runtime if DANGER_GITHUB_API_TOKEN doesn't exist.

[orta]

I'd also 👍 a PR adding support in Danger for first looking at DANGER_GITHUB_API_TOKEN, then checking DANGER_GITHUB_API_TOKEN_OPEN so that you have to do no work on CI there