Description of method assertJsonFileEqualsJsonFile was not corrent and was written in exact opposite way.
Description of method assertJsonStringEqualsJsonFile was not corrent and was written in exact opposite way.
Description of method assertJsonStringEqualsJsonString was not corrent and was written in exact opposite way.
There was a typo in assertContainsOnly method description.

The typo was 'actual value' which should have been 'haystack' instead.
Sync #85 and cleanup.