UPDATEGoldman slashes 2015 oil price forecast as glut grows. .
Oct 27, 2014 1:57pm EDT .
* Goldman says brings forward medium-term bearish outlook * Sees Q1 2015 WTI crude at $75/bbl vs $90/bbl previously
* Sees Q1 2015 Brent at $85/bbl vs $100/bbl previously
* Non-OPEC production growth outside U.S. to top demand growth