add support for custom error messages on failure #35
Description
In order to have a better context in the stack trace, it would be helpful if you could provide a name property to the value to handle assertions better. For example:
assert_that(1 + 2).named('the result of 1 + 2').is_equal_to(4)will raise error message:
Expected [the result of 1 + 2] <3> to be equal to <4>, but was not.
or maybe:
Expected [the result of 1 + 2] to be equal to <4>, but it was <3>.