Doesn't work when autoload is specified as an array

[Dan0sz]

In this package, the autoload section in composer.json is defined as an array:

  "autoload": {
    "psr-4": {
      "TOC\\": ["src", "tests"]
    }
  },

when trying to run mozart compose, the following errors occurs:

PHP Warning:  Array to string conversion in /vendor/coenjacobs/mozart/src/Mover.php on line 122

In Finder.php line 592:
                                                                                                                        
  The "/vendor/caseyamcl/toc/Array" directory does not exist.

I know this is an edgecase, so I fixed it manually now, but it would be nice if it would at least throw a human-readable error when this happens. Or, specify it in our mozart which directory it should choose?