EXHIBIT 2

JOINT FILING AGREEMENT

The undersigned hereby agree to the joint filing of the Amendment No. 3 to Schedule 13D to which this Agreement is attached.

Dated:  August 30, 2016

DISCOVERY GROUP I, LLC,
for itself and as general partner of
DISCOVERY EQUITY PARTNERS, L.P.
By	Michael R. Murphy*
	Michael R. Murphy
	Managing Member

Daniel J. Donoghue*

Daniel J. Donoghue

Michael R. Murphy*

Michael R. Murphy

*By:	/s/ Mark Buckley
	Mark Buckley
	Attorney-in-Fact for Daniel J. Donoghue
	Attorney-in-Fact for Michael R. Murphy