"Could not open input file" when path contains spaces

[gkedzierski]

Humbug crashes with the following error when the path contains spaces, e.g. if the project path is /Users/username/Project Name/:

Stdout:
   > Could not open input file: /Users/username/Project
   >

Humbug version 1.0-dev

PHPUnit 5.7.5, works fine and all tests are passing.