Update coffee-script-source gem 1.6.3 -> 1.7.0

Changes:

When requiring CoffeeScript files in Node you must now explicitly
register the compiler. This can be done with require
'coffee-script/register' or CoffeeScript.register(). Also for
configuration such as Mocha's, use coffee-script/register.

Improved error messages, source maps and stack traces. Source maps now
use the updated //# syntax.

Leading . now closes all open calls, allowing for simpler chaining
syntax.

  $ 'body'
  .click (e) ->
    $ '.box'
    .fadeIn 'fast'
    .addClass '.active'
  .css 'background', 'white'

  Compiles to:

  $('body').click(function(e) {
    return $('.box').fadeIn('fast').addClass('.active');
  }).css('background', 'white');

Added **, // and %% operators and ... expansion in parameter lists and
destructuring expressions.

Multiline strings are now joined by a single space and ignore all
indentation. A backslash at the end of a line can denote the amount of
whitespace between lines, in both strings and heredocs. Backslashes
correctly escape whitespace in block regexes.

Closing brackets can now be indented and therefore no longer cause
unexpected error.

Several breaking compilation fixes. Non-callable literals (strings,
numbers etc.) don't compile in a call now and multiple postfix
conditionals compile properly. Postfix conditionals and loops always
bind object literals. Conditional assignment compiles properly in
subexpressions. super is disallowed outside of methods and works
correctly inside for loops.

Formatting of compiled block comments has been improved.

No more -p folders on Windows.

The options object passed to CoffeeScript is no longer mutated.

Change-Id: I1181ff29df4cefad7399a68842fa7e9b44e04979