Merge pull request #1193 from MatzFan/fix_verbose_tests

fix tests failing when verbose set

Library/Homebrew/dev-cmd/tests.rb

@@ -7,6 +7,8 @@ require "tap"
 module Homebrew
   def tests
     (HOMEBREW_LIBRARY/"Homebrew").cd do
+      ENV.delete "HOMEBREW_VERBOSE"
+      ENV.delete "VERBOSE"
       ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
       ENV["HOMEBREW_DEVELOPER"] = "1"
       ENV["TESTOPTS"] = "-v" if ARGV.verbose?