Switch run_tests.sh to run in parallel by default

This commit switches run_test.sh to run in parallel by default. Since
the tox jobs were moved to parallel by default run_tests.sh should
have the same behavior.

Change-Id: Id144725bfd22d72adbad62772c7496b843dfece8
diff --git a/run_tests.sh b/run_tests.sh
index f995cde..856ce54 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -11,7 +11,7 @@
   echo "  -u, --update             Update the virtual environment with any newer package versions"
   echo "  -s, --smoke              Only run smoke tests"
   echo "  -w, --whitebox           Only run whitebox tests"
-  echo "  -t, --parallel           Run testr parallel"
+  echo "  -t, --serial             Run testr serially"
   echo "  -c, --nova-coverage      Enable Nova coverage collection"
   echo "  -C, --config             Config file location"
   echo "  -p, --pep8               Just run pep8"
@@ -26,7 +26,7 @@
 just_pep8=0
 venv=.venv
 with_venv=tools/with_venv.sh
-parallel=0
+serial=0
 always_venv=0
 never_venv=0
 no_site_packages=0
@@ -38,7 +38,7 @@
 logging=0
 logging_config=etc/logging.conf
 
-if ! options=$(getopt -o VNnfuswtcphdC:lL: -l virtual-env,no-virtual-env,no-site-packages,force,update,smoke,whitebox,parallel,nova-coverage,pep8,help,debug,config:,logging,logging-config: -- "$@")
+if ! options=$(getopt -o VNnfuswtcphdC:lL: -l virtual-env,no-virtual-env,no-site-packages,force,update,smoke,whitebox,serial,nova-coverage,pep8,help,debug,config:,logging,logging-config: -- "$@")
 then
     # parse error
     usage
@@ -61,7 +61,7 @@
     -p|--pep8) let just_pep8=1;;
     -s|--smoke) testrargs="$testrargs smoke";;
     -w|--whitebox) testrargs="$testrargs whitebox";;
-    -t|--parallel) parallel=1;;
+    -t|--serial) serial=1;;
     -l|--logging) logging=1;;
     -L|--logging-config) logging_config=$2; shift;;
     --) [ "yes" == "$first_uu" ] || testrargs="$testrargs $1"; first_uu=no  ;;
@@ -101,10 +101,10 @@
 function run_tests {
   testr_init
   ${wrapper} find . -type f -name "*.pyc" -delete
-  if [ $parallel -eq 1 ]; then
-      ${wrapper} testr run --parallel --subunit $testrargs | ${wrapper} subunit-2to1 | ${wrapper} tools/colorizer.py
-  else
+  if [ $serial -eq 1 ]; then
       ${wrapper} testr run --subunit $testrargs | ${wrapper} subunit-2to1 | ${wrapper} tools/colorizer.py
+  else
+      ${wrapper} testr run --parallel --subunit $testrargs | ${wrapper} subunit-2to1 | ${wrapper} tools/colorizer.py
   fi
 }