Replace all t.ctx with t

Not sure if that's the way to go because, you know, merge conflicts, but
we could do this now.

src/context.rs

@@ -528,7 +528,7 @@ mod tests {
     #[async_std::test]
     async fn test_get_fresh_msgs() {
         let t = TestContext::new().await;
-        let fresh = t.ctx.get_fresh_msgs().await;
+        let fresh = t.get_fresh_msgs().await;
         assert!(fresh.is_empty())
     }
 
@@ -587,14 +587,14 @@ mod tests {
     #[async_std::test]
     async fn no_crashes_on_context_deref() {
         let t = TestContext::new().await;
-        std::mem::drop(t.ctx);
+        std::mem::drop(t);
     }
 
     #[async_std::test]
     async fn test_get_info() {
         let t = TestContext::new().await;
 
-        let info = t.ctx.get_info().await;
+        let info = t.get_info().await;
         assert!(info.get("database_dir").is_some());
     }