remove cov target from Makefile
remove cov target from Makefile

go-plus for Atom has really nice inline cov support

ianrtracey/apex,apex/apex,ianrtracey/apex,llun/apex,DaveBlooman/apex,llun/apex,tobyjoe/apex,llun/apex,mthenw/apex,apex/apex,DaveBlooman/apex,pilwon/apex,DaveBlooman/apex,ianrtracey/apex,llun/apex,DaveBlooman/apex,ianrtracey/apex,llun/apex,pilwon/apex,apex/apex,apex/apex,ianrtracey/apex,pilwon/apex,tobyjoe/apex,DaveBlooman/apex,mthenw/apex,mthenw/apex,apex/apex,apex/apex,DaveBlooman/apex,tobyjoe/apex,mthenw/apex,apex/apex,ianrtracey/apex,llun/apex