Fixed a typo: object.unobserve

[kelleyvanevert]

Ahem.. This typo has crept into the npm release.

[anywhichway]

@kelleyvanevert Why do you think there was a typo? The argument passed into the function is lower case:

Array.unobserve = function(object,callback) {
  -		  return object.unobserve(callback);
  +		  return Object.unobserve(callback);
}