Bump Ipy version to 1.00

Fixes a ValueError when setting an IPv6 address with a subnet.

Signed-off-by: Jelle van der Waa <jelle@archlinux.org>

requirements.txt

 -e git+git://github.com/fredj/cssmin.git@master#egg=cssmin
 Django==2.2.3
-IPy==0.83
+IPy==1.00
 Markdown==3.1
 bencode.py==2.0.0
 django-countries==5.3.3