environs: fixes for gocheck changes.

environs/ec2/config_test.go

 package ec2
 
 import (
         "launchpad.net/goamz/aws"
         . "launchpad.net/gocheck"
         "launchpad.net/juju/go/environs"
         "os"
         "strings"
 )
 
@@ skipping 166 matching lines @@
                 return
         }
         e, err := envs.Open("testenv")
         c.Assert(err, IsNil)
         c.Assert(e, NotNil)
         c.Assert(e, FitsTypeOf, (*environ)(nil), Commentf("environ %q", t.env))
         tconfig := baseConfigResult
         t.mutate(&tconfig)
         c.Check(e.(*environ).config, DeepEquals, &tconfig, Commentf("environ %q", t.env))
 }