Flake: GitPromptServer credential helper parses input without the terminating blank line

[smashwilson]

Test failure seen on Travis on a Linux instance.

  1) GitPromptServer credential helper parses input without the terminating blank line:
     Error: Timeout of 10000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

[kuychaco]

Just saw this again

[kuychaco]

also

  1) GitPromptServer credential helper preserves a provided username:
     Error: Timeout of 10000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

[jasonrudolph]

Encountered again in https://travis-ci.org/atom/github/jobs/267789458.