Avoid hardcoding socket type

[iv-m]

I've seen test failures for python package boto that uses HTTPPretty on my mipsel machines. It turns out that function fake_getaddrinfo from httppretty.core module hardcodes the values for socket family, type and protocol as integers 2, 1 and 6 respectively.

SOCK_DGRAM and SOCK_STREAM are system-specific constants. While you usually get

$ python -c 'import socket; print "SOCK_DGRAM=%s SOCK_STREAM=%s" % (socket.SOCK_DGRAM, socket.SOCK_STREAM);'
SOCK_DGRAM=2 SOCK_STREAM=1

on some systems, you get different values. For example, on most MIPS linux systems, the values are:

$ uname -a
Linux loongson3 4.14.32-l3-def-alt1 #1 SMP PREEMPT Tue Apr 10 11:58:16 UTC 2018 mips64 GNU/Linux
$ python -c 'import socket; print "SOCK_DGRAM=%s SOCK_STREAM=%s" % (socket.SOCK_DGRAM, socket.SOCK_STREAM);'
SOCK_DGRAM=1 SOCK_STREAM=2

So, the value 1 from fake_addrinfo gets interpreted as SOCK_DGRAM on such machines, and tests fail as SOCK_DGRAM type is not supported with IPPROTO_TCP.

To avoid such issues, constants from socket modules should be consistently used instead of the integer values.