The library should not try to autoload the composer deps

[stof]

Currently, the handling of the autoloading is really crappy:

• the expect.php, which define the function also tries to find the composer autoloader and to require it. This is really weird (and it can even cause weird issues as this file is required by the composer autoloader)
• the classes defined in the package are not autoloaded but eager-loaded by the expect.php file

the proper way to deal with the autoloading would be to register a psr-0 rule for the classes and remove all require calls from the expect.php file, keeping only the function definition

[calmdev]

I am running into issues with this right now. Going to look at the PR.