Remove urllib3.disable_warnings

[ninoseki]

Remove urllib3.disable_warnings and use ca_certs provided by certifi because using an insecure connection is a bad idea in terms of security.

• Ref. SSL error when downloading chromium miyakogi/pyppeteer#258 (comment)

[Mattwmaster58]

I believe this is actually not required anymore because Python >= 3.7.4 has patched the root issue that was causing this problem. I'm not sure what versions of 3.6 are affected/fixed. I'll see if I can find a reference for that.

[Mattwmaster58]

Here's the reference: urllib3/urllib3#1682 (comment)
It mentions that 3.6 cannot be fixed, so this PR may have some merit there. @ninoseki Could you base your work off the pup2.1.1 branch? That way we won't have to mess around when it comes to merging pup2.1.1 to dev.

[ninoseki]

Sorry for lack of my research and thank you for your comments.
I will make a PR to pup2.1.1 branch to use certifi in browser_fetcher.py.

[Mattwmaster58]

No problem! The only reason I had the knowledge is that I had to thoroughly investigate a very similar issue recently.

Thank you for your willingness to base your work on the pup2.1.1 branch.

Feel free to request a review from me when you're done.

[Mattwmaster58]

Superceded by #76