environs/jujutest: simplify interface

environs/ec2/live_test.go

 package ec2_test
 
 import (
         "crypto/rand"
         "fmt"
         "io"
         "io/ioutil"
         amzec2 "launchpad.net/goamz/ec2"
         . "launchpad.net/gocheck"
         "launchpad.net/juju-core/environs"
@@ skipping 380 matching lines @@
 }
 
 func hasSecurityGroup(r amzec2.Reservation, g amzec2.SecurityGroup) bool {
         for _, rg := range r.SecurityGroups {
                 if rg.Id == g.Id {
                         return true
                 }
         }
         return false
 }