Use local gulp instead of the global one

tasks.py

@@ -106,17 +106,19 @@ def clean():
 @invoke.task
 def assets(watch=False):
     """Build the assets"""
+    node_bin = "%s/node_modules/.bin" % BASE
+
     # Be sure to have all the dependencies installed
-    if not os.path.exists("%s/node_modules" % BASE):
+    if not os.path.exists(node_bin):
         invoke.run("npm install", pty=True)
 
     if watch:
         try:
-            invoke.run("gulp watch", pty=True)
+            invoke.run("%s/gulp watch" % node_bin, pty=True)
         except KeyboardInterrupt:
             pass
     else:
-        invoke.run("gulp", pty=True)
+        invoke.run("%s/gulp" % node_bin, pty=True)
 
 
 @invoke.task(pre=[assets])