Update Gemfile

Gemfile

@@ -7,25 +7,25 @@ source "https://rubygems.org"
 #
 # This will help ensure the proper Jekyll version is running.
 # Happy Jekylling!
-gem "ffi", 1.17.0
+gem "ffi", "1.16.3"
 gem "jekyll", "4.2.0"
-gem "jekyll-sass-converter", "~> 2.0"
+gem "jekyll-sass-converter", "2.0"
 gem "jekyll-redirect-from"
 gem "kramdown"
 # If you want to use GitHub Pages, remove the "gem "jekyll"" above and
 # uncomment the line below. To upgrade, run `bundle update github-pages`.
 # gem "github-pages", group: :jekyll_plugins
 # If you have any plugins, put them here!
 group :jekyll_plugins do
-  gem "jekyll-feed", "~> 0.12"
+  gem "jekyll-feed", "0.12"
 end
 
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
 # and associated library.
 platforms :mingw, :x64_mingw, :mswin, :jruby do
-  gem "tzinfo", "~> 1.2"
+  gem "tzinfo", "1.2"
   gem "tzinfo-data"
 end
 
 # Performance-booster for watching directories on Windows
-gem "wdm", "~> 0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]
+gem "wdm", "0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]