Fix an example in Task::DSL.evaluate specs
Replace `be_true' matchers with `be true' in specs
Remove deprecated rspec option
Fix some wording issues in Test specs
Revert "Remove deprecated rspec option"

This reverts commit 5e6f5f4861c50c4450095f271943674885476d5f.
Implement condition DSL negated test prefix (no_*)

* 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.
Simplify actions specs
Improve Condition.evaluate specs
Improve wording in Env#initialize specs
Improve small details in specs:

* 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.
Refactor Remote::Environment spec
Move Task::DSL#condition specs to better location
Fix Condition#! specs
Improve Env#target spec
Bump version to 0.1.5
Fix coding standards in Remote::FS specs
Implement `file_write' action
Bump version to 0.1.6
Improve coding standards