simplify if statements with grep

	replace:
		egrep -i "test text" filename
		if [ $? -eq 0 ]; then
	with:
		if cat filename | grep -q "test text"
	add check for if upstream repo is already added

On branch centos7
Changes to be committed:

	modified:   scripts/linux_update.sh
	modified:   scripts/middleman.sh