Added checks to make sure the specified track exists

Added precondition checks to validate input files and paths to return more informative error messages as per #2

node_modules/@jest/console/build/NullConsole.d.ts

@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+import CustomConsole from './CustomConsole';
+export default class NullConsole extends CustomConsole {
+    assert(): void;
+    debug(): void;
+    dir(): void;
+    error(): void;
+    info(): void;
+    log(): void;
+    time(): void;
+    timeEnd(): void;
+    trace(): void;
+    warn(): void;
+}
+//# sourceMappingURL=NullConsole.d.ts.map