fix misspell (#192)

~Fixes #~

**Summary of Changes**

1. fixed misspell `ommited` -> `omitted`

> PS: Make sure your PR includes/updates tests! If you need help with
this part, just ask!

Co-authored-by: Corey Daley <cdaley@redhat.com>

encoder_test.go

@@ -315,7 +315,7 @@ func valsExist(t *testing.T, key string, expect []string, result map[string][]st
 
 func valNotExists(t *testing.T, key string, result map[string][]string) {
 	if val, ok := result[key]; ok {
-		t.Error("Key not ommited. Expected: empty; got: " + val[0] + ".")
+		t.Error("Key not omitted. Expected: empty; got: " + val[0] + ".")
 	}
 }