fixed a test that was broken by the refactor

theano/gof/tests/test_link.py

@@ -4,7 +4,7 @@ from theano.gof import graph
 from theano.gof.graph import Variable, Apply, Constant
 from theano.gof.type import Type
 from theano.gof.op import Op
-from theano.gof import env
+from theano.gof import fg
 from theano.gof import toolbox
 
 from theano.gof.link import *
@@ -75,7 +75,7 @@ def perform_linker(env):
 
 
 def Env(inputs, outputs):
-    e = env.Env(inputs, outputs)
+    e = fg.FunctionGraph(inputs, outputs)
     return e