Change coverage/cross compile trigger for travis.yml
Change coverage/cross compile trigger for travis.yml

Doing code coverage/cross compile for a single Go release. As of now,
if we were to introduce Go 1.8 in the matrix, we would do code
coverage (which may be ok) and create release (which would not be
ok) for 2 Go releases since were were using >= comparison.
This change ensures that we do for only 1.7.x for now.

apcera/gnatsd,glycerine/gnatsd,mitghi/gnatsd,ericpromislow/gnatsd,nats-io/gnatsd,glycerine/hnatsd,ericpromislow/gnatsd,wallyqs/gnatsd,glycerine/hnatsd,wallyqs/gnatsd,glycerine/gnatsd,glycerine/hnatsd,mitghi/gnatsd,nats-io/gnatsd,apcera/gnatsd