Fix TSLint issues

As this is the starter project it should be provided without any errors.
This commit restructures some code to solve the TSLint issues.

src/utils/ErrorMapper.ts

@@ -38,8 +38,8 @@ export class ErrorMapper {
     while (match = re.exec(stack)) {
       if (match[2] === "main") {
         const pos = this.consumer.originalPositionFor({
-          line: parseInt(match[3], 10),
-          column: parseInt(match[4], 10)
+          column: parseInt(match[4], 10),
+          line: parseInt(match[3], 10)
         });
 
         if (pos.line != null) {
@@ -75,7 +75,8 @@ export class ErrorMapper {
       } catch (e) {
         if (e instanceof Error) {
           if ("sim" in Game.rooms) {
-            console.log(`<span style='color:red'>Source maps don't work in the simulator - displaying original error<br>${_.escape(e.stack)}</span>`)
+            const message = `Source maps don't work in the simulator - displaying original error`;
+            console.log(`<span style='color:red'>${message}<br>${_.escape(e.stack)}</span>`);
           } else {
             console.log(`<span style='color:red'>${_.escape(this.sourceMappedStackTrace(e))}</span>`);
           }
@@ -84,6 +85,6 @@ export class ErrorMapper {
           throw e;
         }
       }
-    }
+    };
   }
 }