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/nice-try/CHANGELOG.md

@@ -0,0 +1,21 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [1.0.5] - 2018-08-25
+
+### Changed
+
+- Removed `prepublish` script from `package.json`
+
+## [1.0.4] - 2017-08-08
+
+### New
+
+- Added a changelog
+
+### Changed
+
+- Ignore `yarn.lock` and `package-lock.json` files