minor css linting
fix navbar active selectors (bug 1090027)
if available, use PORT from environment variable for server (bug 1090044)
pull in common tests from commonplace (bug 1080895)
Merge pull request #745 from ngokevin/testtemp

pull in common tests from commonplace (bug 1080895)
Merge pull request #744 from cvan/allow-port-to-be-changed

if available, use PORT from environment variable for server (bug 1090044)
Merge pull request #740 from cvan/css-linting

minor css linting
use marketplace-gulp repo (bug 1086947)
Merge pull request #746 from ngokevin/mktgulp

use marketplace-gulp repo (bug 1086947)
Merge pull request #741 from cvan/navbar-active-selectors

fix navbar active selectors (bug 1090027)
fix Dockerfile