requirements_common.txt: Upgrade iptools==0.6.1 for Python 3 and ipv4…

…/ipv6 (#1680)

* https://pypi.org/project/iptools/

https://pypi.org/project/iptools is currently [failing our build process](https://travis-ci.org/internetarchive/openlibrary/jobs/464164657#L894) on Python 3 because of a syntax error.  This PR upgrades to a Python 3 compatible release.

* iptools.validate_ip() —> iptools.ip4.validate_ip(

To track with changes to the iptools API.

* iptools.ipv4.validate_cidr()

* Update iprange.py

openlibrary/core/iprange.py

@@ -137,21 +137,21 @@ def add_ip_range(self, ip_range, value):
         # Convert ranges in CIDR format into (start, end) tuple
         if isinstance(ip_range, six.string_types) and "/" in ip_range:
             # ignore bad value
-            if not iptools.validate_cidr(ip_range):
+            if not iptools.ipv4.validate_cidr(ip_range):
                 return
-            ip_range = iptools.cidr2block(ip_range)
+            ip_range = iptools.ipv4.cidr2block(ip_range)
 
         # Find the integer representation of first 2 parts of the start and end IPs
         if isinstance(ip_range, tuple):
             # ignore bad ips
-            if not iptools.validate_ip(ip_range[0]) or not iptools.validate_ip(ip_range[1]):
+            if not iptools.ipv4.validate_ip(ip_range[0]) or not iptools.ipv4.validate_ip(ip_range[1]):
                 return
 
             # Take the first 2 parts of the begin and end ip as integer
-            start = iptools.ip2long(ip_range[0]) >> 16
-            end = iptools.ip2long(ip_range[1]) >> 16
+            start = iptools.ipv4.ip2long(ip_range[0]) >> 16
+            end = iptools.ipv4.ip2long(ip_range[1]) >> 16
         else:
-            start = iptools.ip2long(ip_range) >> 16
+            start = iptools.ipv4.ip2long(ip_range) >> 16
             end = start
 
         # for each integer in the range add an entry.
@@ -169,7 +169,7 @@ def add_ip_range_text(self, ip_range_text, value):
 
     def __getitem__(self, ip):
         # integer representation of first 2 parts
-        base = iptools.ip2long(ip) >> 16
+        base = iptools.ipv4.ip2long(ip) >> 16
         for ip_range, value in self.ip_ranges.get(base, {}).items():
             if ip in ip_range:
                 return value

requirements_common.txt

@@ -4,7 +4,7 @@ DBUtils==1.3
 flake8==3.6.0
 Genshi==0.6
 gunicorn==19.9.0
-iptools==0.4.0
+iptools==0.6.1
 internetarchive==1.8.1
 lxml==4.2.5
 pyflakes==2.0.0