Add additional failing to_h sequence_of test

[adfoster-r7]

I believe this is a separate bug to: #45 - so I thought I'd create a separate example test failure snippet. Let me know if I should close this off or raise a separate issue 💯

Current to_h output:

{
  LdapMessage: {
    message_id: 2,
    protocol_op: {
      # TODO: Wrong
      "": ["ldap://example.com/ou=People,dc=example,dc=com"],
      diagnostic_message:
        "0000202B: RefErr: DSID-0310082F, data 0, 1 access points\n\tref 1: 'example.com'\n\x00",
      matched_dn: "",
      result_code: "referral"
    }
  }
}

Expected - Key not blank:

expected = {
  LdapMessage: {
    message_id: 2,
    protocol_op: {
      # key present:
      referral: ["ldap://example.com/ou=People,dc=example,dc=com"],
      diagnostic_message:
        "0000202B: RefErr: DSID-0310082F, data 0, 1 access points\n\tref 1: 'example.com'\n\x00",
      matched_dn: "",
      result_code: "referral"
    }
  }
}

Wireshark example:

[adfoster-r7]

This gets serialized incorrectly as:

                "": ["ldap://example.com/ou=People,dc=example,dc=com"],

[adfoster-r7]

Expected:

Suggested change

	"": ["ldap://example.com/ou=People,dc=example,dc=com"],
	"referral": ["ldap://example.com/ou=People,dc=example,dc=com"],

[adfoster-r7]

Issue in the PR description is fixed by #44 - will close 👍