go: initialise go mod

This allows a native `go build` and `go test`.

Signed-off-by: David Scott <dave@recoil.org>

Author: djs55

go.mod

@@ -0,0 +1,8 @@
+module github.com/moby/hyperkit
+
+go 1.14
+
+require (
+	github.com/mitchellh/go-ps v1.0.0
+	golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/mitchellh/go-ps v1.0.0 h1:i6ampVEEF4wQFF+bkYfwYgY+F/uYJDktmvLPf7qIgjc=
+github.com/mitchellh/go-ps v1.0.0/go.mod h1:J4lOc8z8yJs6vUwklHw2XEIiT4z4C40KtWVN3nvg8Pg=
+golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6 h1:X9xIZ1YU8bLZA3l6gqDUHSFiD0GFI9S548h6C8nDtOY=
+golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=