Update liquid dependency

[rstacruz]

liquid is now in 3.0, with github-pages using 2.6.

when using github-pages with jekyll-slim, you get:

Bundler could not find compatible versions for gem "liquid":
  In snapshot (Gemfile.lock):
    liquid (= 2.6.2)

  In Gemfile:
    github-pages (>= 0) ruby depends on
      liquid (= 2.6.2) ruby

    github-pages (>= 0) ruby depends on
      jekyll (= 2.4.0) ruby depends on
        liquid (~> 2.6.1) ruby

    jekyll-slim (>= 0) ruby depends on
      sliq (>= 0) ruby depends on
        liquid (~> 2.5.5) ruby

[dmitryzuev]

I had updated dependencies, and I'll appreciate if you'll check if it works good. Check this out: https://github.com/dmitryzuev/sliq/tree/feature-versions-update

Add this to your Gemfile:
gem 'sliq', git: 'git@github.com:dmitryzuev/sliq.git', branch: 'feature-versions-update'

I had also made pull request to this repo: #3

[rstacruz]

that should be github: 'dmitryzuev/sliq' since we can't access your private git URL.

thanks for the update @dmitryzuev!