Update the nokogiri dependency?

[abartov]

Hi!

There's a security vulnerability in nokogiri fixed in version 1.10.4. This gem requires ~>1.8, holding back upgrades of nokogiri. Could you release a version requiring the newer nokogiri, or just >1.8 open-endedly? Thanks!

[mvz]

Hi @abartov, the specification ~> 1.8 already allows 1.10.4, since it specifies the minor version number must be 8 or heigher.

[satoryu]

Updated the dependency 👍
4628bbd