[Security] Update jQuery

[b4D8]

Current package comes with jQuery 1.12.4 which was release in May 2016 and is known to have vulnerabilities...

I ran Lighthouse on my website and got the following warning:

Includes front-end JavaScript libraries with known security vulnerabilities 4 vulnerabilities detected

Library Version	Vulnerability Count	Highest Severity
[email protected]	4	Medium

Probably an even better option would be to remove this dependency (#VanillaJS).