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/babel-plugin-jest-hoist/README.md

@@ -0,0 +1,33 @@
+# babel-plugin-jest-hoist
+
+Babel plugin to hoist `jest.disableAutomock`, `jest.enableAutomock`, `jest.unmock`, `jest.mock`, calls above `import` statements. This plugin is automatically included when using [babel-jest](https://github.com/facebook/jest/tree/master/packages/babel-jest).
+
+## Installation
+
+```sh
+$ yarn add --dev babel-plugin-jest-hoist
+```
+
+## Usage
+
+### Via `babel.config.js` (Recommended)
+
+```js
+module.exports = {
+  plugins: ['jest-hoist'],
+};
+```
+
+### Via CLI
+
+```sh
+$ babel --plugins jest-hoist script.js
+```
+
+### Via Node API
+
+```javascript
+require('@babel/core').transform('code', {
+  plugins: ['jest-hoist'],
+});
+```