Additionally install test-requirements with pip_install

When moving to Python 3, we also need to install test-requriements
to allow projects to install any python 3 test dependencies they
might be missing otherwise.

Change-Id: I2d19aa2f7ec8de869a82aa7764ab72cc8693101f

Author: Sirushti Murugesan

inc/python

@@ -124,7 +124,7 @@ function pip_install {
         $@
 
     # Also install test requirements
-    local test_req="$@/test-requirements.txt"
+    local test_req="${!#}/test-requirements.txt"
     if [[ -e "$test_req" ]]; then
         echo "Installing test-requirements for $test_req"
         $sudo_pip \