Fixed so website runs without therubyracer

Gemfile

@@ -11,7 +11,7 @@ source "https://rubygems.org"
 
 
 gem "jekyll", "< 4.0"
-gem 'sassc', '~> 2.1.0'
+gem 'sassc', '~> 2.4.0'
 
 # If you have any plugins, put them here!
 group :jekyll_plugins do
@@ -28,7 +28,6 @@ group :jekyll_plugins do
   gem 'remark'
   gem 'jekyll-mermaid'
   gem 'uglifier'
-  gem 'therubyracer'
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem

Gemfile.lock

@@ -96,7 +96,6 @@ GEM
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
-    libv8 (3.16.14.19)
     liquid (4.0.3)
     liquid-tag-parser (1.9.0)
       extras (~> 0.3)
@@ -124,7 +123,6 @@ GEM
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    ref (2.0.0)
     regexp_parser (2.1.1)
     remark (0.3.2)
       hpricot (~> 0.8.2)
@@ -153,9 +151,6 @@ GEM
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    therubyracer (0.12.3)
-      libv8 (~> 3.16.14.15)
-      ref
     thread_safe (0.3.6)
     typhoeus (1.4.0)
       ethon (>= 0.9.0)
@@ -189,8 +184,8 @@ DEPENDENCIES
   kramdown-parser-gfm
   remark
   rubocop (~> 0.50)
+  sassc (~> 2.4.0)
   sprockets (~> 3.7)
-  therubyracer
   tzinfo-data
   uglifier
   w3c_validators (~> 1.3)