Add proxy support through options

[mjishnu]

from pypdl import Downloader

def main():
    # create a new downloader object
    dl = Downloader()

    # Use custom headers to set user-agent
    dl.headers = {"User-Agent":"Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0"}
    # Use custom proxies
    dl.proxies = {
                    "http": "http://10.10.1.10:3128",
                    "https": "https://10.10.1.10:1080",
                }
    # Use authentication for proxy
    dl.auth = ("user","pass")

    # start the download
    dl.start(
        url='https://speed.hetzner.de/100MB.bin',
        filepath='100MB.bin',
        num_connections=10,
        display=True,
        multithread=True,
        block=True,
        retries=3,
        retry_func=None,
    )

if __name__ == '__main__':
    main()

added support for using proxy, you can also pass the proxy by passing it as a parameter toDownloader()