invalid memory address or nil pointer dereference when rampage endpoint is hit

[nimeshsubramanian]

This is the error I get:

2016/12/22 10:19:10 http: panic serving IP.IP.IP.IP:51686: runtime error: invalid memory address or nil pointer dereference
goroutine 20 [running]:
net/http.(*conn).serve.func1(0xc820104600)
	/usr/local/go/src/net/http/server.go:1389 +0xc1
panic(0x7aa9e0, 0xc82000a0d0)
	/usr/local/go/src/runtime/panic.go:443 +0x4e9
main.NOUN_Rampage.ServeHTTP(0x7f00dc16c9c0, 0xc820110410, 0xc8201302a0)
	/Users/mhausenblas/Dropbox/dev/work/src/github.com/dcos-labs/drax/api.go:62 +0xbfb
main.(*NOUN_Rampage).ServeHTTP(0xa38920, 0x7f00dc16c9c0, 0xc820110410, 0xc8201302a0)
	<autogenerated>:2 +0xab
net/http.(*ServeMux).ServeHTTP(0xc8200110b0, 0x7f00dc16c9c0, 0xc820110410, 0xc8201302a0)
	/usr/local/go/src/net/http/server.go:1910 +0x17d
net/http.serverHandler.ServeHTTP(0xc820018180, 0x7f00dc16c9c0, 0xc820110410, 0xc8201302a0)
	/usr/local/go/src/net/http/server.go:2081 +0x19e
net/http.(*conn).serve(0xc820104600)
	/usr/local/go/src/net/http/server.go:1472 +0xf2e
created by net/http.(*Server).Serve
	/usr/local/go/src/net/http/server.go:2137 +0x44e

my post call is to Myip:7777/rampage?level=0

0.2.0 version works fine for me.