Rewrite the store interface (#1335)

* WIP store rewrite

* Fix memory store tests

* Store hard expiry times rather than duration!

* Clarify memory test

* Add limit to store interface

* Implement suffix option

* Don't return nils from noop store

* Fix syncmap

* Start fixing store service

* wip service and cache

* Use _ for special characters in cockroachdb namespace

* Improve cockroach namespace comment

* Use service name as default store namespace

* Fixes

* Implement Store Scope

* Start fixing etcd

* implement read and write with expiry and prefix

* Fix etcd tests

* Fix cockroach store

* Fix cloudflare interface

* Fix certmagic / cloudflare store

* comment lint

* cache isn't implemented yet

* Only prepare DB staements once

Co-authored-by: Ben Toogood <ben@micro.mu>
Co-authored-by: ben-toogood <bentoogood@gmail.com>

store/cache/cache_test.go

@@ -0,0 +1,15 @@
+package cache
+
+// import "testing"
+
+// func TestCache(t *testing.T) {
+// 	c := NewStore()
+// 	if err := c.Init(); err != nil {
+// 		//t.Fatal(err)
+// 	}
+// 	if results, err := c.Read("test"); err != nil {
+// 		//t.Fatal(err)
+// 	} else {
+// 		println(results)
+// 	}
+// }