[Greendns] Replace deprecated resolver.query by resolver.resolve

Usages of `resolver.query` are deprecated[1][2][3] and should
be replaced by `resolver.resolve`.

Fix #818

[1] https://dnspython.readthedocs.io/en/latest/whatsnew.html#id8
[2] https://github.com/rthalley/dnspython/blob/adfc942725bd36d28ec53f7e5480ace9eb543bd8/dns/resolver.py#L1360
[3] https://github.com/rthalley/dnspython/blob/adfc942725bd36d28ec53f7e5480ace9eb543bd8/dns/resolver.py#L1596

eventlet/support/greendns.py

@@ -409,7 +409,7 @@ def end():
         # https://github.com/nameko/nameko/issues/392
         # https://github.com/eventlet/eventlet/issues/363
         if len(qname) == 1:
-            step(self._resolver.query, qname.concatenate(dns.name.root),
+            step(self._resolver.resolve, qname.concatenate(dns.name.root),
                  rdtype, rdclass, tcp, source, raise_on_no_answer=False)
 
         return end()
@@ -623,7 +623,7 @@ def getnameinfo(sockaddr, flags):
 
     if is_ipv4_addr(host):
         try:
-            rrset = resolver.query(
+            rrset = resolver.resolve(
                 dns.reversename.from_address(host), dns.rdatatype.PTR)
             if len(rrset) > 1:
                 raise socket.error('sockaddr resolved to multiple addresses')
@@ -636,7 +636,7 @@ def getnameinfo(sockaddr, flags):
                 raise EAI_NONAME_ERROR
     else:
         try:
-            rrset = resolver.query(host)
+            rrset = resolver.resolve(host)
             if len(rrset) > 1:
                 raise socket.error('sockaddr resolved to multiple addresses')
             if flags & socket.NI_NUMERICHOST: