Add an update option to run_tests.sh

This commit adds an update option to run_tests.sh. This option
is used to rerun install_venv.py on an already installed venv.
This will then just update out of date packages with pip.

Change-Id: I49a1cbcb62e7f429eca3efe949b8aa90507723c4

run_tests.sh

@@ -8,6 +8,7 @@ function usage {
   echo "  -N, --no-virtual-env     Don't use virtualenv.  Run tests in local environment"
   echo "  -c, --coverage           Generate coverage report"
   echo "  -f, --force              Force a clean re-build of the virtual environment. Useful when dependencies have been added."
+  echo "  -u, --update             Update the virtual environment with any newer package versions"
   echo "  -p, --pep8               Just run pep8"
   echo "  -P, --no-pep8            Don't run pep8"
   echo "  -l, --pylint             Just run pylint"
@@ -26,6 +27,7 @@ function process_option {
     -V|--virtual-env) let always_venv=1; let never_venv=0;;
     -N|--no-virtual-env) let always_venv=0; let never_venv=1;;
     -f|--force) let force=1;;
+    -u|--update) update=1;;
     -p|--pep8) let just_pep8=1;;
     -P|--no-pep8) no_pep8=1;;
     -l|--pylint) let just_pylint=1; let never_venv=1; let always_venv=0;;
@@ -48,6 +50,7 @@ noseargs=
 wrapper=""
 coverage=0
 verbose=0
+update=0
 
 for arg in "$@"; do
   process_option $arg
@@ -123,6 +126,10 @@ then
     echo "Cleaning virtualenv..."
     rm -rf ${venv}
   fi
+  if [ $update -eq 1 ]; then
+    echo "Updating virtualenv..."
+    python tools/install_venv.py
+  fi
   if [ -e ${venv} ]; then
     wrapper="${with_venv}"
   else