Allow completion of all methods when MockBuilder has no setMethods call

[King2500]

This change allows method completion of all methods when MockBuilder has no setMethods call. (Every method of the class is stubbed in this case)

$mock = $this->getMockBuilder(\ThomasSchulz\ClockUtil\Clock::class)
             ->getMock();
$mock->expects($this->once())->method('<caret>');

Also works:

$mock = $this->getMock(\ThomasSchulz\ClockUtil\Clock::class);
$mock->expects($this->once())->method('<caret>');

[Ma27]

ping @maxfilatov

[maxfilatov]

Merged to branch unstable-2