chore(crystal-1.0): Update for Crystal 1.0

* Crystal and shards >= 1.0 require all external shards to specify
  compatbility via the `crystal` directive in  `shard.yml`.
* Update the coffeescript compiler to the latest 1.X release of
  1.12.8 (sorry, no 2.X support).
* Add a `CoffeeScript::Source.bundled_version` static method that
  can be used to detect the bundled source version of the CS compiler.
* Release version 2.0.

NOTE: we've changed how this shard is versioned - it's still a
      semantic versioning scheme, but we no longer directly replicate
      the bundled coffeescript compiler version. Instead, use
      the `CoffeeScript::Source.bundled_version` to check the compiler
      version.

README.md

@@ -1,7 +1,7 @@
 CoffeeScript Source
 ===================
 
-This repository contains a basic [Crystal](http://crystal-lang.org) shard that contains the raw javascript for the [CoffeeScript](https:/jashkenas/coffeescript) compiler. This shard's version will directly match the version of the corresponding CoffeeScript compiler.
+This repository contains a basic [Crystal](http://crystal-lang.org) shard that contains the raw javascript for the [CoffeeScript](https:/jashkenas/coffeescript) compiler.
 
 Most of this code was taken from Ruby's [coffee-script-source](https://rubygems.org/gems/coffee-script-source)'s gem and Crystalized.
 
@@ -14,7 +14,7 @@ In your `shard.yml`:
 dependencies:
  coffee-script-source:
  github: jessedoyle/coffee-script-source
- version: ~> 1.12.6
+ version: ~> 2.0
 ```
 
 the execute `shards install`.
@@ -25,17 +25,24 @@ Usage
 ```crystal
 require "coffee-script-source"
 
-CoffeeScript::Source.bundled_path # => somewhere...
+CoffeeScript::Source.bundled_path # => somewhere...
+CoffeeScript::Source.bundled_version # => "X.X.X"
 ```
 
+Notes
+=====
+
+* Currently, this shard supports the 1.X releases of CoffeeScript. PRs are welcome - please see the discussion [here](https:/jessedoyle/coffee-script-source/pull/3#issuecomment-779522699) for context.
+
 Maintenance
 ===========
 
 For future reference, when a new CoffeeScript version is released:
 
 1. Create a new branch on this repo, then checkout the created branch.
 2. From the repo's root directory execute: `bin/build-coffee-script 1.x.x`.
-3. Commit and merge as usual. Don't forget to add the correct release tags (eg. `v1.10.0`).
+3. Update the `bundled_version` static method in [`src/coffee_script_source.cr`](https:/jessedoyle/coffee-script-source/blob/master/src/coffee_script_source.cr).
+4. Commit and merge as usual. Don't forget to add the correct release tags (eg. `v1.10.0`).
 
 License
 =======

shard.yml

@@ -1,7 +1,8 @@
 name: coffee-script-source
-version: 1.12.6
+version: 2.0.0
 
 authors:
  - Jesse Doyle <[email protected]>
 
+crystal: '>= 0.35.1'
 license: MIT

src/coffee_script_source.cr

@@ -3,5 +3,9 @@ module CoffeeScript
  def self.bundled_path
  File.expand_path("../js/coffee-script.js", __FILE__)
  end
+
+ def self.bundled_version
+ "1.12.8"
+ end
  end
 end