Start the mitmproxy

def start_proxy(self):
        """Start the mitmproxy
        """

        self.runner.info_log("Starting proxy...")

        self.proxy_port = self.browser_config.get('proxy_port', 8080)

        self.network_data_path = os.path.join(
            self.runner.runner_dir,
            'network_capture'
        )
        create_dir_if_doesnt_exist(self.network_data_path)

        self.local_proxy_output_path = os.path.join(
            self.network_data_path,
            string_to_filename('%s.data' % self.testname)
        )
        self.local_proxy_log_path = os.path.join(
            self.network_data_path,
            string_to_filename('%s.mitm' % self.testname)
        )

        self.remote_proxy_output_path = string_to_filename(
            '%s.data' % self.testname
        )
        self.remote_proxy_log_path = string_to_filename(
            '%s.mitm' % self.testname
        )

        path_to_mitmproxy = self.browser_config.get(
            "mitmproxy:path",
            'mitmdump'
        )

        filter_ = self.browser_config.get("mitmproxy:filter")
        command = [
            'DISPLAY=:0',
            'nohup',
            path_to_mitmproxy,
            "-p",
            "%s" % str(self.proxy_port),
            "-w",
            "'%s'" % self.remote_proxy_output_path
        ]

        if filter_:
            command.append(filter_)

        command.extend(['>', "'%s'" % self.remote_proxy_log_path, '2>&1'])
        command.append('&')

        self.execute_command(' '.join(command))