1. University of Toronto, 27 King’s College Circle, Toronto, Ontario M5S 1A1, Canada
2. Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
3. Institute of Experimental Physics, Graz University of Technology, Graz 8010, Austria
4. LIGO-Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States