Use one job less on CI

CHANGELOG.md

@@ -13,6 +13,7 @@ Version 61:
 * Tidy up http-crawl example
 * Add multi_port to server-framework
 * Tidy up resolver calls
+* Use one job on CI
 
 API Changes:
 

scripts/build-and-test.sh

@@ -43,6 +43,9 @@ elif [[ $(uname -s) == "Linux" ]]; then
   if [[ "${TRAVIS}" == "true" && ${NUM_PROCESSORS:=2} > ${num_jobs} ]]; then
       num_jobs=$NUM_PROCESSORS
   fi
+  if [[ "$TRAVIS" == "true" ]] && (( "$num_jobs" > 1)); then
+      num_jobs=$((num_jobs - 1))
+  fi
 fi
 
 echo "using toolset: $CC"