Fix tests and docker build

Fixes #914.

Rakefile

@@ -3,6 +3,7 @@
 require 'bundler/setup'
 require 'thor'
 
+Bundler.require :default
 $LOAD_PATH.unshift 'lib'
 
 task :default do
@@ -13,8 +14,6 @@ end
 namespace :assets do
   desc 'Compile all assets'
   task :precompile do
-    Bundler.require
-
     load 'tasks/docs.thor'
     DocsCLI.new.prepare_deploy
 

lib/docs.rb

@@ -1,5 +1,5 @@
 require 'bundler/setup'
-Bundler.require :docs
+Bundler.require :default, :docs
 
 require 'active_support'
 require 'active_support/core_ext'