[#71] Orchestra\Extension\Publisher::execute() shouldn't populate messages and do redirect

Signed-off-by: crynobone <crynobone@gmail.com>
[#71] Fixed Fatal error: Call-time pass-by-reference has been removed

Signed-off-by: crynobone <crynobone@gmail.com>
[#71] Fixed type hinting issue.

Signed-off-by: crynobone <crynobone@gmail.com>
[#88] Create Orchestra\Installer\Requirement class

Signed-off-by: crynobone <crynobone@gmail.com>
[#88] Bad recursive.

Signed-off-by: crynobone <crynobone@gmail.com>
[#88] Fixed installation process.

Signed-off-by: crynobone <crynobone@gmail.com>