Allow custom chain

Full Changelog: v0.1.0...v0.2.0

v0.1.0

go/iptables-api.go: add push/clean up methods

• address issue #2
• clean up methods with a switch of r.Method
• add PUT method for push function

README.md: document push function (issue #2)

iptables-api/iptables-api-arm

• rebuild based on current iptables-api.go

v0.0.3

• added "Rest" type functions with POST / DELETE
• improved documentation
• optimized code

v0.0.2

• add ipv6 support

Initial Release

Day 1... most certainly beta =)