Migrate to go modules

**What**
- Initial migration to go modules using the default output from i
  `go mod tidy`

Signed-off-by: Lucas Roesler <[email protected]>

go.mod

@@ -0,0 +1,27 @@
+module github.com/openfaas/faas-swarm
+
+go 1.15
+
+require (
+	github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78 // indirect
+	github.com/Microsoft/hcsshim v0.8.10 // indirect
+	github.com/containerd/containerd v1.4.1 // indirect
+	github.com/containerd/continuity v0.0.0-20200928162600-f2cc35102c2a // indirect
+	github.com/docker/cli v0.0.0-20180829155626-a8186778137d
+	github.com/docker/distribution v2.6.0-rc.1.0.20170726174610-edc3ab29cdff+incompatible
+	github.com/docker/docker v17.12.0-ce-rc1.0.20200916142827-bd33bbf0497b+incompatible
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/docker/go-units v0.4.0
+	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
+	github.com/golang/protobuf v1.4.2 // indirect
+	github.com/google/go-cmp v0.5.3 // indirect
+	github.com/gorilla/mux v1.8.0
+	github.com/morikuni/aec v1.0.0 // indirect
+	github.com/opencontainers/image-spec v1.0.1 // indirect
+	github.com/opencontainers/runc v0.1.1 // indirect
+	github.com/openfaas/faas-provider v0.15.1
+	golang.org/x/net v0.0.0-20201006153459-a7d1128ccaa0
+	golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e // indirect
+	google.golang.org/grpc v1.33.2 // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
+)