Contact page: Make translation-ready

* Updates `app/views/contacts/new.html.haml`
  to evaluate translation strings

* Add translation strings in `config/locales/contacts.en.yml`

* Also updates `config/locales/simple_form.en.yml`
  to translate input forms on Contact page

* Difficult to make "Thank you for contacting us" page
  translation-ready, so ignored that for now.

app/views/contacts/new.html.haml

@@ -1,7 +1,7 @@
 - if @contact.restroom_name.present?
-  %h1 Request Edit for #{@contact.restroom_name} Restroom
+  %h1= t('.request-edit')
 - else
-  %h1 Contact
+  %h1= t('.contact-title')
 = simple_form_for @contact, html: {class: 'form-vertical headroom'} do |f|
   %p
   = f.input :name, :required => true
@@ -10,6 +10,6 @@
   .hidden
     = f.hidden_field :restroom_id, :required => false
     = f.hidden_field :restroom_name, :required => false
-    = f.hidden_field :nickname, :hint => 'Leave this field blank!'
+    = f.hidden_field :nickname, :hint => t('.leave-this-field-blank')
   .form-actions
-    = f.button :submit, 'Send message', :class=> "linkbutton"
+    = f.button :submit, :class=> "linkbutton"

config/locales/contacts.en.yml

@@ -0,0 +1,6 @@
+en:
+  contacts:
+    new:
+      request-edit: 'Request Edit for #{@contact.restroom_name} Restroom'
+      contact-title: 'Contact'
+      leave-this-field-blank: 'Leave this field blank!'

config/locales/simple_form.en.yml

@@ -1,3 +1,6 @@
+# See this documentation: https://github.com/plataformatec/simple_form#i18n
+# And this StackOverflow answer: https://stackoverflow.com/questions/35906089/changing-simple-form-submit-button-i18n-text
+
 en:
   simple_form:
     "yes": 'Yes'
@@ -10,6 +13,19 @@ en:
       # html: '<abbr title="required">*</abbr>'
     error_notification:
       default_message: "Please review the problems below:"
+
+    labels:
+      defaults:
+        name: 'Name'
+        email: 'Email'
+        message: 'Message'
+
+  helpers:
+    submit:
+      contact:
+        # This is the "Submit message" button on the "Contact" page.
+        create: 'Submit message'
+
     # Labels and hints examples
     # labels:
     #   defaults: