Grab package requirements

def requires(self):
        """Grab package requirements
        """
        for line in self.SLACKBUILDS_TXT.splitlines():
            if line.startswith(self.line_name):
                sbo_name = line[17:].strip()
            if line.startswith(self.line_req):
                if sbo_name == self.name:
                    return line[21:].strip().split()