Nokogiri security alert: requires nokogiri gem update to version 1.8.1 or newer

[vohmar]

Known critical severity security vulnerability detected in nokogiri < 1.8.1 defined in Gemfile.lock.Gemfile.lock update suggested: nokogiri ~> 1.8.1.Always verify the validity and compatibility of suggestions with your codebase. | Known critical severity security vulnerability detected in nokogiri < 1.8.1 defined in Gemfile.lock. | Gemfile.lock update suggested: nokogiri ~> 1.8.1. | Always verify the validity and compatibility of suggestions with your codebase.
Known critical severity security vulnerability detected in nokogiri < 1.8.1 defined in Gemfile.lock.
Gemfile.lock update suggested: nokogiri ~> 1.8.1.
Always verify the validity and compatibility of suggestions with your codebase.

http://sgmail.githubmail.com/wf/click?upn=lYxq-2FYU7yocrdKNILYalBmg6f2FmLIR-2BtKy2yBtrpIQHg2x8LEJbjR9H9oDezTwF9uWV1PpUapTDb0XciWG7FFn4jaChFyrkAZPU5nJHPIY-3D_ExdJbNVRHqTG04xEJMh-2BkMyZ39KwK1E0uoDjJTpzQk0YEViGzFsaQj28g-2Bx47yz51yknlpeCnm74B2tCw-2Fwpw4giGO0Dn8-2BF2RvA3iLIo8twXnk2IukALs01MWVrxGbN102NzZLveEBVjPChs8zFIdJ2x6po6zOrQ-2FWK6z-2F5EDr-2FKRG3l-2FVjsks-2B1RUJPVAUWGj90HeCntyEAlfznEsh924Q9LJWlCL8M5if4h71frNcS0HtgdVZQzznE00yLik96a1jGMemyu0yumlxP6gYWA-3D-3D