fix Jekyll version number in readme

Author: SethTisue

README.md

@@ -6,7 +6,7 @@ It's a static site generated by [Jekyll](https://github.com/mojombo/jekyll), and
 
 ## Dependencies
 
-This site uses a Jekyll, a Ruby framework. The required Jekyll version is 3.1.6.
+This site uses a Jekyll, a Ruby framework. The required Jekyll version is 3.3.0.
 
 ## Building the site
 
@@ -33,9 +33,9 @@ you used to run Jekyll.
 
 ### Option 2) Building with global Jekyll
 
-Install Jekyll 3.1.6 on your system using RubyGems:
+Install Jekyll 3.3.0 on your system using RubyGems:
 
-    gem install jekyll -v 3.1.6
+    gem install jekyll -v 3.3.0
 
 After cloning, `cd` into the directory where you cloned this repository and run: