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-jasmine2/build/setup_jest_globals.d.ts

@@ -0,0 +1,17 @@
+/**
+ * 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 { Config } from '@jest/types';
+import { Plugin } from 'pretty-format';
+export declare type SetupOptions = {
+    config: Config.ProjectConfig;
+    globalConfig: Config.GlobalConfig;
+    localRequire: (moduleName: string) => Plugin;
+    testPath: Config.Path;
+};
+declare const _default: ({ config, globalConfig, localRequire, testPath, }: SetupOptions) => import("../../jest-snapshot/build/State").default;
+export default _default;
+//# sourceMappingURL=setup_jest_globals.d.ts.map