refactor(tools): convert scripts from npm to yarn

re-enable Angular CLI's build-optimizer

Author: Splaktar

tools/build-themes.sh

@@ -13,7 +13,7 @@ for FILE in $FILES
 do
   FILENAME=${FILE#$INPUT_PATH}
   BASENAME=${FILENAME%.scss}
-  $(npm bin)/node-sass $FILE > $DEST_PATH/$BASENAME.css
+  yarn node-sass $FILE > $DEST_PATH/$BASENAME.css
 done
 
 echo Finished building CSS.

tools/deploy.sh

@@ -30,8 +30,6 @@ echo ""
 
 read -rp "Press <ENTER> to continue.."
 
-npm run build-themes
-
-"$(npm bin)"/ng build --aot --prod --build-optimizer=false
-"$(npm bin)"/firebase use $projectId
-"$(npm bin)"/firebase deploy
+yarn prod-build
+yarn firebase use $projectId
+yarn firebase deploy