Use Oj for faster JSON parsing

Gemfile

@@ -3,6 +3,7 @@ source 'https://rubygems.org'
 gem 'dotenv',             '~> 2.0.2'
 gem 'mrkt',               '~> 0.6.0'
 gem 'full-name-splitter', '~> 0.1.2'
+gem 'oj',                 '~> 2.17'
 gem 'sentry-raven',       '~> 0.15'
 gem 'sinatra',            '~> 1.4.6', require: 'sinatra/base'
 gem 'unicorn'

Gemfile.lock

@@ -11,6 +11,7 @@ GEM
     mrkt (0.6.1)
       faraday_middleware (~> 0.9.1)
     multipart-post (2.0.0)
+    oj (2.17.5)
     rack (1.6.4)
     rack-protection (1.5.3)
       rack
@@ -34,9 +35,10 @@ DEPENDENCIES
   dotenv (~> 2.0.2)
   full-name-splitter (~> 0.1.2)
   mrkt (~> 0.6.0)
+  oj (~> 2.17)
   sentry-raven (~> 0.15)
   sinatra (~> 1.4.6)
   unicorn
 
 BUNDLED WITH
-   1.11.2
+   1.13.2

app.rb

-require 'json'
+require 'oj'
 
 require './lib/marketo_client'
 require './lib/user'
@@ -19,8 +19,8 @@ class MarketoTools < Sinatra::Base
   # See http://gitlab.com/help/system_hooks/system_hooks
   post '/system_hook' do
     begin
-      params = JSON.parse(request.body.read)
-    rescue JSON::ParserError
+      params = Oj.load(request.body.read)
+    rescue Oj::ParseError
       params = {}
     end