Update module github.com/patrickmn/go-cache to v2

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/go-test/deep v1.0.7
 	github.com/mattes/migrate v0.0.0-20180508041624-4768a648fbd9 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
-	github.com/patrickmn/go-cache v0.0.0-20180815053127-5633e0862627
+	github.com/patrickmn/go-cache/v2 v2.1.0
 	github.com/pquerna/otp v1.3.0
 	github.com/prometheus/client_golang v1.10.0
 	github.com/sethvargo/go-password v0.2.0