Stop using Babel source gem, which is no longer updated

Gemfile

@@ -52,7 +52,6 @@ gem 'ember-rails', '0.18.5'
 gem 'ember-source'
 gem 'ember-handlebars-template', '0.7.5'
 gem 'barber'
-gem 'babel-transpiler'
 
 gem 'message_bus'
 

Gemfile.lock

@@ -51,10 +51,6 @@ GEM
       jmespath (~> 1.0)
     aws-sdk-resources (2.5.3)
       aws-sdk-core (= 2.5.3)
-    babel-source (5.8.34)
-    babel-transpiler (0.7.0)
-      babel-source (>= 4.0, < 6)
-      execjs (~> 2.0)
     barber (0.11.2)
       ember-source (>= 1.0, < 3)
       execjs (>= 1.2, < 3)
@@ -392,7 +388,6 @@ DEPENDENCIES
   active_model_serializers (~> 0.8.3)
   annotate
   aws-sdk
-  babel-transpiler
   barber
   better_errors
   binding_of_caller

lib/es6_module_transpiler/tilt/es6_module_transpiler_template.rb

@@ -1,5 +1,4 @@
 require 'execjs'
-require 'babel/transpiler'
 require 'mini_racer'
 
 module Tilt
@@ -27,7 +26,7 @@ module Tilt
     def self.create_new_context
       # timeout any eval that takes longer than 15 seconds
       ctx = MiniRacer::Context.new(timeout: 15000)
-      ctx.eval("var self = this; #{File.read(Babel::Transpiler.script_path)}")
+      ctx.eval("var self = this; #{File.read("#{Rails.root}/vendor/assets/javascripts/babel.js")}")
       ctx.eval("module = {}; exports = {};");
       ctx.load("#{Rails.root}/lib/es6_module_transpiler/support/es6-module-transpiler.js")
       ctx.attach("rails.logger.info", proc{|err| Rails.logger.info(err.to_s)})