GoogleMapもBootstrapも適用されず、JSエラーが出る

どのタイミングでそうなったかはわからないのですが、突然GoogleMapも出ず、Bootstrapのデザインも適用されなくなりました。画面上のイメージはこのような感じです。

Bootstrapは正しく適用されているとこんなデザインになります。

Mapが出てないのはJSのエラー（下記）が出ているからのようなのですが、複数回JSを読ませたような節は思い当たりません。
You have included the Google Maps API multiple times on this page. This may cause unexpected errors

関連しそうな箇所で言うとapplication.jsはこちら

//= require jquery
//= require jquery_ujs
//= require turbolinks
//= require underscore
//= require bootstrap
//= require gmaps/google

Viewのapplication.html.slimはこちら

doctype 5
html(lang="en")
  head
    meta(charset="utf-8")
    meta(http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1")
    meta(name="viewport" content="width=device-width, initial-scale=1.0")
    title= content_for?(:title) ? yield(:title) : "vegewel"
    = csrf_meta_tags
    / Le HTML5 shim, for IE6-8 support of HTML elements
    /[if lt IE 9]
      = javascript_include_tag "http://html5shim.googlecode.com/svn/trunk/html5.js"
    = yield(:page_stylesheet) if content_for?(:page_stylesheet)
    = stylesheet_link_tag "flatly", :media => "all"
    = javascript_include_tag "application"
    = if defined?(@temp)
      = render :partial => @temp + '.html'
  body

    nav.navbar.navbar-default.navbar-fixed-top
      .container-fluid
        .navbar-header
          button.navbar-toggle.collapsed data-target="#navbarEexample2" data-toggle="collapse" type="button"
            span.sr-only Toggle navigation
            span.icon-bar
            span.icon-bar
            span.icon-bar
          a.navbar-brand href="/"
            img alt="Vegewel" src="/logo4.png" style=("height: 30px;")
        #navbarEexample2.collapse.navbar-collapse
          ul.nav.navbar-nav
            li
              = link_to I18n.t('frontpage_by_area'), (url_for controller:'/area')
            li
              = link_to I18n.t('frontpage_by_restaurant'), (url_for controller:'/restaurant')
            li
              = link_to I18n.t('frontpage_by_menu'), (url_for controller:'/menu')
            li
              = link_to I18n.t('frontpage_by_genre'), (url_for controller:'/genre')
            li
              = link_to I18n.t('frontpage_by_restraunttype'), (url_for controller:'/restaurant_type' )
            p.navbar-text
              = link_to 'JP', "/ja"
              |  | 
              = link_to 'EN', "/en"

    h3 aaa
    - if user_signed_in?
      |  Logged in as
      strong
        = current_user.name
      | .
      = link_to 'Edit profile', edit_user_registration_path, :class => 'navbar-link'
      |  |

      |  |
      = link_to "Logout", destroy_user_session_path, :method => :delete, :class => 'navbar-link'
    - else
      = link_to "Sign up", new_user_registration_path, :class => 'navbar-link'
      |  |
      = link_to "Login", new_user_session_path, :class => 'navbar-link'
    - if notice.present?
      p.notice.alert.alert-info
        = notice
    - if alert.present?
      p.alert.alert-warning
        = alert
    = yield
    /!
      | Javascripts
      | \==================================================
    /! Placed at the end of the document so the pages load faster
    = javascript_include_tag "flatly"
    = yield(:page_javascript) if content_for?(:page_javascript)

  footer

該当箇所のViewはこんな感じです（Mapのところのみ）。

tr
      th.col-xs-6.col-sm-3.col-md-1 = t :restaurant_list_map
      td.col-xs-12.col-sm-6.col-md-3
        #map if @restaurant.lat.present?

【追記】
application.html.slimの中から = if defined?(@temp)で読み込んでいるテンプレートはこちらです。ここに地図関連の情報も載せています。

head
    meta charset="utf-8"
    meta http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1"
    meta name="viewport" content="width=device-width, initial-scale=1.0"
    title= content_for?(:title) ? yield(:title) : "Vegewel"
    = csrf_meta_tags
    = stylesheet_link_tag "application", :media => "all"
    = favicon_link_tag 'apple-touch-icon-144x144-precomposed.png', :rel => 'apple-touch-icon-precomposed', :type => 'image/png', :sizes => '144x144'
    = favicon_link_tag 'apple-touch-icon-114x114-precomposed.png', :rel => 'apple-touch-icon-precomposed', :type => 'image/png', :sizes => '114x114'
    = favicon_link_tag 'apple-touch-icon-72x72-precomposed.png', :rel => 'apple-touch-icon-precomposed', :type => 'image/png', :sizes => '72x72'
    = favicon_link_tag 'apple-touch-icon-precomposed.png', :rel => 'apple-touch-icon-precomposed', :type => 'image/png'
    = favicon_link_tag 'favicon.ico', :rel => 'shortcut icon'
    = javascript_include_tag "application"

    script src="//maps.google.com/maps/api/js?v=3.23&key=AIzaSyCgBL4ep6_BcDS3ffBf9Tz5ZTHaaZ4Y3bg"
    script src="//cdn.rawgit.com/mahnunchik/markerclustererplus/master/dist/markerclusterer.min.js"
    script src='//cdn.rawgit.com/printercu/google-maps-utility-library-v3-read-only/master/infobox/src/infobox_packed.js'

JSの順番なのかわからないのですが、調べてもTurbolinksが悪そうとかは出てくるのですが見当もつきかねるので是非皆さんのお知恵を拝借したいです。
どうかよろしくお願いします。