Add explicit panic for prelude errors

Maybe I want to handle this better in the future, but for now just panic
if the prelude is bad for some reason.

schala-lang/language/src/schala.rs

@@ -51,7 +51,10 @@ impl Schala {
     let mut s = Schala::new_blank_env();
 
     let request = ComputationRequest { source: prelude, debug_requests: HashSet::default() };
-    s.run_computation(request);
+    let response = s.run_computation(request);
+    if let Err(msg) = response.main_output {
+      panic!("Error in prelude, panicking: {}", msg);
+    }
     s
   }