fix(ci): remove gecko from webdriver

Apparently we are hitting all sorts of rate limits while downloading
gecko from Github that fails our tests.  We don't even use gecko.  This
removes gecko to try and overcome the problem.

sh/dependencies.sh

@@ -6,7 +6,7 @@ yarn install
 
 ./node_modules/.bin/bower install --quiet
 ./node_modules/.bin/gulp build
-./node_modules/.bin/webdriver-manager update
+./node_modules/.bin/webdriver-manager update --gecko false
 
 # cd into the built directory
 cd bin