* Fix coding standards;
* Simplify some expectations (eq instead of be matcher);
* Expect identity on block instead of calling;
* Change some before call as oneliners;
* Avoid shadowing variable names;
* Improve wording where needed.
* Allow no_* to be used for every tests in condition DSL:
condition { no_has_env :shell, '/bin/sh' };
* Modify Test constructor to accept negated: named argument, implement
#negated? and #pass?;
* Rename #success? to #verify in all test classes.