Fix coding standards in Remote (extra parentheses)
Remove Condition::DSL.evaluate method
Remove Recipe::DSL.evaluate method
Remove Task::DSL.evaluate method
Implement `macro' recipe keyword
Bump version to 0.1.7
Simplify Remote::Environment with factory method:

* Implement .new_from_string factory class method;
* Rename private method #parse_from_string as class method
  .string_to_hash;
* Remove argument kind detection logic in constructor.
Fix gemspec:

* Remove $LOAD_PATH modification;
* Dup VERSION string;
* Add a real summary.
Improve `echo' action cucumber feature wording
Replace env.output interface with an IO like object