Drop mongo support (#23)

go.mod

@@ -11,23 +11,18 @@ require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
 	github.com/go-redis/redis/v8 v8.6.0
 	github.com/go-redsync/redsync/v4 v4.0.4
-	github.com/golang/snappy v0.0.2 // indirect
 	github.com/gomodule/redigo v2.0.0+incompatible
 	github.com/google/uuid v1.2.0
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/kelseyhightower/envconfig v1.4.0
-	github.com/klauspost/compress v1.11.7 // indirect
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/pkg/errors v0.9.1
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/streadway/amqp v1.0.0
 	github.com/stretchr/testify v1.7.0
 	github.com/urfave/cli v1.22.5
-	github.com/xdg/stringprep v1.0.0 // indirect
-	go.mongodb.org/mongo-driver v1.4.6
 	go.opencensus.io v0.22.6 // indirect
-	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad // indirect
 	golang.org/x/oauth2 v0.0.0-20210201163806-010130855d6c // indirect
 	gopkg.in/yaml.v2 v2.4.0
 )