Update Gemfile.lock
Update Gemfile.lock

Update jekyll version to 3.7.4 to remove security vulnerability CVE-2018-17567
ucanozyurteri/ucanozyurteri.github.io,JoanCano/joancano.io,ucanozyurteri/ucanozyurteri.github.io,agusmakmun/agusmakmun.github.io,JoeGannon/Blog,JoanCano/joancano.io,JoeGannon/Blog,agusmakmun/agusmakmun.github.io,ucanozyurteri/ucanozyurteri.github.io,JoanCano/joancano.io,agusmakmun/agusmakmun.github.io