Support for testing "outer" config

[zeleznypa]

I'm using a Phinx as a part of the Nette framework.
There is a Dependency Ijection contaier, where I can setup the Phinx configuration directly without the 'phinx.yml' file, using the setConfig method.

Unfortunately the Test command force to use the file.

phinx/src/Phinx/Console/Command/Test.php

Line 62 in 26753bd

$this->loadConfig($input, $output);

It will be nice to have a possibility to check the connection with this configuration.
Everything that I need is to encapsulate this line like this:

if($this->hasConfig() === false) {
    $this->loadConfig($input, $output);
}

[MasterOdin]

Looking quickly, all the other commands make a call to $this->bootstrap($input, $output);, which then does:

phinx/src/Phinx/Console/Command/AbstractCommand.php

Lines 125 to 127 in 26753bd

	if (!$this->hasConfig()) {
	$this->loadConfig($input, $output);
	}

So yeah, no reason to have a similar if check within the test command.