DoResponse method should return correct error.

When json.Unmarshal fails in the DoResponse method it should returns the associated error. Currently it returns the error generated from ioutil.ReadAll with isn't directly related. I think that the DoResponse method should return an error if the ioutil.ReadAll fails and not attempt the json.Unmarshal. These unreported cause the error propagation to fail which results nil pointer issues later.

Please let me know if there is anything additional I need to do to get this merged into the main branch.
Merge pull request #43 from CheRuisiBesares/patch-1

DoResponse method should return correct errors.
Update README.md

trying out the counter
update to docs
go fmt
- added support for Update API
Merge pull request #47 from edazdarevic/master

- added support for Update API
add stops to go routines in bulk indexor when it shuts down
Correct indexor -> indexer in code and documentation

This is a breaking change, but it seems better to do it now than later.
As far as I know Go doesn't have a nice way to alias everything
involved, but let me know if you'd like me to do so anyway.
Merge pull request #50 from fractalcat/master

Correct indexor -> indexer in code and documentation
Fix code that triggers go vet errors
Merge pull request #51 from mattoddie/fix-go-vet-errors

Fix code that triggers go vet errors
Merge pull request #49 from araddon/upstream_master

add stops to go routines in bulk indexor when it shuts down
convert BulkIndexor -> bulkIndexer
Exists shouldn't return error.

Exists shouldn't return error when the document isn't found. Currently it does because Do and then DoResponse is trying to Unmarshal the body of this request. Because the request verb is HEAD there is no payload and the following error occurs "unexpected end of JSON input". Passing nil here will prevent the  conditions here (https://github.com/mattbaird/elastigo/blob/master/api/request.go#L104) from being met and therefore prevent this error. This doesn't seem to interfere with anything. Let me know if I have overlooked anything.
update unit testing to github.com/bmizerany/assert
Removed a fmt.Println
Merge pull request #53 from CheRuisiBesares/patch-1

Exists shouldn't return error.
Merge pull request #55 from araddon/upstream_master

update unit testing to github.com/bmizerany/assert
Merge branch 'master' of https://github.com/mattbaird/elastigo