Remove superfluous 'set +x' commands.

Author: gilesgas

jenkins/scripts/kill.sh

@@ -5,4 +5,3 @@ echo '(written to ".pidfile"), all of which were conducted when "deliver.sh"'
 echo 'was executed.'
 set -x
 kill $(cat .pidfile)
-set +x

jenkins/scripts/test.sh

@@ -18,4 +18,3 @@ echo 'application renders satisfactorily. This command actually invokes the test
 echo 'runner Jest (https://facebook.github.io/jest/).'
 set -x
 npm test
-set +x