Do some cleanup in the test, so it doesn't fail in my shell

cmd/tendermint/commands/root_test.go

@@ -25,6 +25,11 @@ const (
 // isolate provides a clean setup and returns a copy of RootCmd you can
 // modify in the test cases
 func isolate(cmds ...*cobra.Command) cli.Executable {
+	os.Unsetenv("TMHOME")
+	os.Unsetenv("TM_HOME")
+	os.Unsetenv("TMROOT")
+	os.Unsetenv("TM_ROOT")
+
 	viper.Reset()
 	config = cfg.DefaultConfig()
 	r := &cobra.Command{