youtube-dl isn't able to use SSL:
```
$ youtube-dl https://www.youtube.com/watch?v=YE7VzlLtp-4
[youtube] YE7VzlLtp-4: Downloading webpage
WARNING: Unable to download webpage: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)>
[youtube] YE7VzlLtp-4: Downloading API JSON
ERROR: Unable to download API page: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)> (caused by URLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)')))
```