Fix blinking keymap testcase
Fix blinking keymap testcase

If the build is slow, and/or build package closes the build
panel due to its timeout, the toggle panel will really open
the panel - causing the testcase to fail. Defer to always letting
the panel be auto-closed and just wait for it to be closed.

MadcapJake/atom-build,sphaerophoria/atom-build,noseglid/atom-build,oli-obk/atom-build