Split make targets and update provisioning accordingly

Makefile

@@ -1,9 +1,16 @@
 install:
+	make install_composer
+	make install_assets
+
+install_composer:
 	composer install
+
+install_assets:
 	rm -rf ./node_modules
 	rm -rf ./www/assets
 	rm -rf ./www/bower_components
 	npm install
+	./node_modules/bin/gulp build
 
 config:
 	@php bin/console compile:configuration