Tag v1.0.0

[elliotchance]

It's really annoying that this project gets picked up and added:

require (
	github.com/fnproject/fdk-go v0.0.0-20190102214815-bd24a5aa63cf
)

$ go mod why github.com/fnproject/fdk-go
# github.com/fnproject/fdk-go
github.com/kounta/superfluid/v6/node_modules/serverless/lib/plugins/create/templates/fn-go/hello
github.com/fnproject/fdk-go

At least tag it so the go.sum file has a version.

[rdallman]

yep, working on it: #54 - thanks for issue to track