Evaluate glide-hash result without reading $?.

validate-glide is called with errexit enabled (in script/make.sh that
sources validate-glide), which means that grep returning a non-zero exit
code will cause the script to terminate prematurely. Thus, we will never
get to the point where we see the error message.

The fix is to embed the grep check directly inside the if statement.

script/validate-glide

@@ -2,8 +2,7 @@
 
 source "$(dirname "$BASH_SOURCE")/.validate"
 
-grep `glide-hash` glide.lock
-if [ $? -eq 0 ]; then
+if grep -q "$(glide-hash)" glide.lock; then
 	echo 'Congratulations! glide.lock is unchanged.'
 else
 	{