switch to mongodb, add drag&drop

backend/Cargo.toml

@@ -11,12 +11,18 @@ default-run = "backend"
 actix-web = "4"
 actix-web-lab = "^0"
 actix-files = "0.6"
+actix-cors = "0.6.4"
+actix-session = { version = "0.7.2", features = ["cookie-session"] }
 env_logger = "0.9.0"
 log = "0.4"
-diesel = { version = "1.4.8", features = ["postgres", "r2d2"] }
-diesel_migrations = "1.4"
 dotenv = "0.15.0"
 walkdir = "2"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 common = { path = "../common" }
+uuid = { version = "1", features = ["v4", "serde"] }
+
+[dependencies.mongodb]
+version = "2.2.0"
+default-features = false
+features = ["async-std-runtime"]