Panic map concurrent read + write

[nathanielc]

fatal error: concurrent map read and map write

goroutine 7 [running]:
runtime.throw(0xf96e00, 0x21)
        /usr/lib/go/src/runtime/panic.go:547 +0x90 fp=0xc8204dcc40 sp=0xc8204dcc28
runtime.mapaccess2(0xb5ff60, 0xc8201c44e0, 0xc8204dcde0, 0x1464dc0, 0x0)
        /usr/lib/go/src/runtime/hashmap.go:343 +0x5a fp=0xc8204dcc88 sp=0xc8204dcc40
github.com/influxdata/kapacitor.(*TaskMaster).forkPoint(0xc82012c820, 0xc82060f406, 0x6, 0xc82045694f, 0x6, 0xc820456959, 0x6, 0xeb3958, 0x0, 0x0, ...)
        /home/nathanielc/projects/kapacitor/src/github.com/influxdata/kapacitor/task_master.go:512 +0x49b fp=0xc8204dce78 sp=0xc8204dcc88
github.com/influxdata/kapacitor.(*TaskMaster).runForking(0xc82012c820, 0xc82015a770)
        /home/nathanielc/projects/kapacitor/src/github.com/influxdata/kapacitor/task_master.go:480 +0xbf fp=0xc8204dcfa0 sp=0xc8204dce78
runtime.goexit()
        /usr/lib/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc8204dcfa8 sp=0xc8204dcfa0
created by github.com/influxdata/kapacitor.(*TaskMaster).stream
        /home/nathanielc/projects/kapacitor/src/github.com/influxdata/kapacitor/task_master.go:473 +0x26b

goroutine 1 [chan receive]:
main.(*Main).Run(0xc82024bf10, 0xc82000a310, 0x2, 0x2, 0x0, 0x0)
        /home/nathanielc/projects/kapacitor/src/github.com/influxdata/kapacitor/cmd/kapacitord/main.go:96 +0xc02
main.main()
        /home/nathanielc/projects/kapacitor/src/github.com/influxdata/kapacitor/cmd/kapacitord/main.go:41 +0x361