Tweaks so gulp runs properly on bang.
Tweaks so gulp runs properly on bang.

We need to pass the `ENVIRONMENT` environment variable down so gulp runs a dev build when called through the *Update Environment* Jenkins job.

viastudio/Silencio,viastudio/Silencio,viastudio/Silencio,nickstewart95/Silencio,nickstewart95/Silencio,nickstewart95/Silencio