v2.0.0

* Breaking: Remove `general`, `time`, `string` and `color` root keys and all of their methods
* Breaking: `env.merge()` no longer supports relative paths
* New: `breadcrumbs` key and three public methods on it, available client and server
* New: `env.merge()` first looks for env.js and then env.json in `process.cwd()`
* New: `env.merge()` supports js files in addition to json files
* New: `isNode` and `isClient` keys on root `thehelp-core` object client and server
Add date to 2.0.0 release