Adding Postgresql driver and basic config structures.

config/config.go

@@ -15,6 +15,13 @@ type StackConfiguration struct {
 	UserHmacEnv               string
 	AuthedRateLimitConfig     string
 	UnauthedRateLimitConfig   string
+
+	DbDialect        string
+	DbUsername       string
+	DbPasswordSecret string
+	DbUrl            string
+	DbPort           string
+	DbName           string
 }
 
 var Environment = os.Getenv("STACK_ENVIRONMENT")

config/dev/conf.json

@@ -4,5 +4,12 @@
     "AdminHmacEnv": "ADMIN_HMAC_ENV",
     "UserHmacEnv": "USER_HMAC_ENV",
 	"AuthedRateLimitConfig": "ratelimit.auth.json",
-	"UnauthedRateLimitConfig": "ratelimit.unauth.json"
+	"UnauthedRateLimitConfig": "ratelimit.unauth.json",
+
+    "DbDialect": "sqlite",
+    "DbUrl": "prepack.db",
+    "DbUsername": "",
+    "DbPasswordSecret": "",
+    "DbPort": "",
+    "DbName": ""
 }