Fix amzn-2 and centos-7 missing virtualenv

init

@@ -89,6 +89,13 @@ if [[ "$ci" == "false" ]]; then
     fi
     python3 -m pip install virtualenv
   fi
+else
+  if [ "${DISTRO}" = "centos-7" ] || [ "${DISTRO}" = "amzn-2" ]; then
+    if python3 -m pip show virtualenv >/dev/null 2>/dev/null; then
+      python3 -m pip uninstall -y virtualenv
+    fi
+    python3 -m pip install virtualenv
+  fi
 fi
 
 # setup gql_behave dependencies