figure out how to test the deploy command about oghliner

[marco-c]

Looks interesting, I'll take a stab at it.

[mykmelez]

Marco, these tests broke the next time I merged a change to master (https://travis-ci.org/mozilla/oghliner/builds/85199186), because the tmp dir was apparently preserved across builds:

2. Deploy should update the gh-pages branch in the origin repo and publish files to it:
   Error: EEXIST, file already exists 'tmp'
   at Error (native)
   at Object.fs.mkdirSync (fs.js:747:18)
   at Context. (test/testDeploy.js:49:8)

[brendandahl]

The temp folder/file creation library I used in https://github.com/mozilla/oghliner/pull/63/files#diff-c792d04edfea01487109cfd6450c9ef8R4 worked pretty well.

[marco-c]

@mykmelez I think it was a timeout, which then caused the "tmp" directory to be preserved and thus the second test to fail.
It's likely that the test could actually need more time, as in this successful build (https://travis-ci.org/mozilla/oghliner/builds/85199186, which is yours retriggered) the test took 673ms (which is relatively close to the current timeout of 2 seconds).

Let's file a new issue if it happens again.
I'll also submit a PR to avoid failing following tests when the first runs out of time.