Lots of URL normalization.

So it doesn't matter if you have a trailing / or not.
diff --git a/openstack/utils/choose_version_test.go b/openstack/utils/choose_version_test.go
index 4a8a443..b724ee8 100644
--- a/openstack/utils/choose_version_test.go
+++ b/openstack/utils/choose_version_test.go
@@ -53,7 +53,7 @@
 		t.Errorf("Expected %#v to win, but %#v did instead", v3, v)
 	}
 
-	expected := testhelper.Endpoint() + "v3.0"
+	expected := testhelper.Endpoint() + "v3.0/"
 	if endpoint != expected {
 		t.Errorf("Expected endpoint [%s], but was [%s] instead", expected, endpoint)
 	}
@@ -76,7 +76,7 @@
 		t.Errorf("Expected %#v to win, but %#v did instead", v2, v)
 	}
 
-	expected := testhelper.Endpoint() + "v2.0"
+	expected := testhelper.Endpoint() + "v2.0/"
 	if endpoint != expected {
 		t.Errorf("Expected endpoint [%s], but was [%s] instead", expected, endpoint)
 	}