Update Bundler to 2.0.2 (#3567)

Gemfile

@@ -1,13 +1,6 @@
 source "https://rubygems.org"
 ruby "2.6.3"
 
-# Enforce git to transmitted via https.
-# workaround until bundler 2.0 is released.
-git_source(:github) do |repo_name|
-  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
-  "https://github.com/#{repo_name}.git"
-end
-
 group :production do
   gem "nakayoshi_fork", "~> 0.0.4" # solves CoW friendly problem on MRI 2.2 and later
   gem "rack-host-redirect", "~> 1.3" # Lean and simple host redirection via Rack middleware

Gemfile.lock

@@ -974,4 +974,4 @@ RUBY VERSION
    ruby 2.6.3p62
 
 BUNDLED WITH
-   1.17.3
+   2.0.2