Update test script to always use nvm if possible

scripts/test.sh

@@ -68,6 +68,12 @@ unlock_device() {
 cleanup
 trap cleanup EXIT
 
+# Use a consistent version of Node if possible.
+if [ -s "${HOME}/.nvm/nvm.sh" ]; then
+  . "${HOME}/.nvm/nvm.sh"
+  nvm use 5.4.0 || true
+fi
+
 case "$TARGET" in
 "jsdoc")
   npm run jsdoc
@@ -108,9 +114,6 @@ case "$TARGET" in
      exit 0
   fi
 
-  [ -s "${HOME}/.nvm/nvm.sh" ] && . "${HOME}/.nvm/nvm.sh"
-  nvm use 5.4.0 || true
-
   pushd react-native/android
   ./gradlew installarchives
   popd