move upstream into own package

server/upstream/2rm.go

@@ -0,0 +1,10 @@
+package upstream
+
+import "github.com/OrlovEvgeny/go-mcache"
+
+// branchTimestampCache stores branch timestamps for faster cache checking
+var branchTimestampCache = mcache.New()
+
+// fileResponseCache stores responses from the Gitea server
+// TODO: make this an MRU cache with a size limit
+var fileResponseCache = mcache.New()