Fix to run on updated version of urfave/cli

[l3x]

[]cli.Command was changed to []*cli.Command in v2

These changes resolve https://github.com/marouni/adr/issues/3

[marouni]

@l3x Any idea why the build is failing ?

[l3x]

Yes. I believe it's because the Go module PR locked the urfave/cli version at v1.20.0.

I've noticed others have run into this issue and it's likely because most people are running Go, relying on GOPATH to resolve the dependencies: That'll grab the latest versions-- urfave/cli is on version 2 -- which breaks b/c the existing adr code depends on version 1.x syntax in two places.

I noticed that Travis executes export GO111MODULE="on" to turn on Go Module support prior to running go build ./

You can see the Travis build log here.

A reasonable solution would be to update the go.mod and go.sum files to match a more current release.

If you're not in a hurry, I can look at updating that this weekend.

In the meantime, folks complaining about errors installing adr can run export GO111MODULE="on" before installing adr.

[marouni]

@l3x

If you're not in a hurry, I can look at updating that this weekend. That sounds awesome, this way it will fix the issue out of the box. Thx