Specifying a standards file using absolute path and extension fails

[mariuswilms]

When trying to to invoke the phpca command like this phpca [...] --standard /path/to/other/standard.ini [...], the standard is not recognized because the wrong part of the path is checked for the extension.

This fix works for me: http://github.com/davidpersson/phpca/commit/2fffbf1e72540e3c00d78e1cd02079e341562528