Update src/ZFTool/Model/Skeleton.php

Support for proxy using envvar HTTP_PROXY
Support for proxy

Support for proxy using envvar HTTP_PROXY
[#25] CS/logic fixes

- Added docblock to new method
- return early from method if condition is not met
Fixing relative path of the target directory

Wrong classmaps were generated because the classmap target file and
the directory to be crawled were uncomparable.