chore: Added go.mod and go.sum

go.mod

@@ -0,0 +1,26 @@
+module github.com/yokoe/herschel
+
+go 1.17
+
+require (
+	github.com/pkg/errors v0.9.1
+	golang.org/x/oauth2 v0.0.0-20220630143837-2104d58473e0
+	google.golang.org/api v0.86.0
+)
+
+require (
+	cloud.google.com/go/compute v1.7.0 // indirect
+	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.1.0 // indirect
+	github.com/googleapis/gax-go/v2 v2.4.0 // indirect
+	go.opencensus.io v0.23.0 // indirect
+	golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e // indirect
+	golang.org/x/sys v0.0.0-20220624220833-87e55d714810 // indirect
+	golang.org/x/text v0.3.7 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20220624142145-8cd45d7dbd1f // indirect
+	google.golang.org/grpc v1.47.0 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+)