Queries the DNS server and returns the result

Examples:

iex> DNS.query("tungdao.com")                              # <= Queries for A records
iex> DNS.query("tungdao.com", :mx)                         # <= Queries for the MX records
iex> DNS.query("tungdao.com", :a, { "208.67.220.220", 53}) # <= Queries for A records, using OpenDNS

Resolves the answer for a DNS query

Example:

iex> DNS.resolve("tungdao.com")                      # {:ok, [{1, 1, 1, 1}]}
iex> DNS.resolve("tungdao.com", :txt)                # {:ok, [['v=spf1 a mx ~all']]}
iex> DNS.resolve("tungdao.com", :a, {"8.8.8.8", 53}) # {:ok, [{1, 1, 1, 1}]}