Fix afterEach/tearDown sync calling
Merge pull request #263 from avaly/fix/after-each-no-arguments

Fix afterEach/tearDown sync calling
0.5.23
fixed selenium server not starting from nightwatch in version 2.43
show the server error response #265
fixed jshint error
0.5.24
Option to disable screenshot data in logs

Setting the option `screenshot_data` in one of the `test_sestings` environment
causes the screenshot base64 data to be outputted or hidden from the logs.

Fixes #256