Datastore DB

Googles Cloud Firestore in Datastore mode - High Level Rust API (with serde support!)

API Preview

```rust // MODEL

[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]

pub struct TodoItem { pub name: String, pub title: String, } // MODEL METADATA impl EntityKey for TodoItem { fn entitykindkey() -> String { String::from("TodoItem") } fn entitynamekey(&self) -> String { self.name.clone() } } // INIT let db = DatastoreClient::new().unwrap(); let item = TodoItem { name: String::from("test"), title: String::from("lorem ipsum") }; // GO! db.upsert(item); ```