[release.sh] Do not run tests by default

We are at the point that testing takes waay too long for a release cycle, and fails way too often.
Tests through travis are a better indicator than testing just before release.

devscripts/release.sh

@@ -14,9 +14,9 @@
 
 set -e
 
-skip_tests=false
+skip_tests=true
-if [ "$1" = '--skip-test' ]; then
+if [ "$1" = '--run-tests' ]; then
-    skip_tests=true
+    skip_tests=false
     shift
 fi