Add parentheses to method tags

PHPSpec needs to receive correct @method tags... So with parentheses.
If there is no parentheses, we've got this issue : 
```
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string sentence
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string sentences
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string paragraph
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string paragraphs
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string text
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string date
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string time
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string dateTimeBetween
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: boolean boolean
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: int randomNumber
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: mixed randomKey
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: int numberBetween
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: float randomFloat
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string randomElement
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string numerify
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string lexify
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string bothify
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string toLower
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: string toUpper
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: mixed optional
2014-02-03T14:55:32+01:00 ERR (3): @method contained invalid contents: UniqueGenerator unique
PHP Parse error:  syntax error, unexpected '(', expecting identifier (T_STRING) in /home/pedro/Works/FriendlyContexts/vendor/phpspec/prophecy/src/Prophecy/Doubler/Generator/ClassCreator.php(48) : eval()'d code on line 33
```
So I've added parentheses and it works.