Fix tasks.py due to an Invoke breaking change

tasks.py

@@ -27,6 +27,12 @@ PYTHON = "python3"
 PROJECT = "uitwww"
 
 
+# This is because invoke can't keep backward compatibility...
+_invoke_v = invoke.__version__.split(".")
+if int(_invoke_v[0]) == 0 and int(_invoke_v[1]) <= 12:
+    invoke.task = invoke.ctask
+
+
 def create_env(name, requirements=False, self=False, force=False):
     """Create a new virtual environment"""
     path = os.path.join(BASE, "build", "envs", name)
@@ -48,7 +54,7 @@ def create_env(name, requirements=False, self=False, force=False):
 
 
 @invoke.task
-def clean():
+def clean(ctx):
     """Clean all the build things"""
     for dir in "build", "%s.egg-info" % PROJECT:
         path = os.path.join(BASE, dir)
@@ -104,7 +110,7 @@ def clean():
 
 
 @invoke.task
-def assets(watch=False):
+def assets(ctx, watch=False):
     """Build the assets"""
     node_bin = "%s/node_modules/.bin" % BASE
 
@@ -122,13 +128,13 @@ def assets(watch=False):
 
 
 @invoke.task(pre=[assets])
-def devel():
+def devel(ctx):
     """Setup the development environment"""
     create_env("devel", self=True, force=True)
 
 
 @invoke.task(pre=[assets])
-def build():
+def build(ctx):
     """Create a new build"""
     env = create_env("build", requirements=True)