Update Formtastic and formtastic-bootstrap

Previous version of Formtastic was giving following deprecation warning:
`#column_for_attribute` will return a null object for non-existent
columns in Rails 5. Use #has_attribute? if you need to check for
an attribute's existence.

Guide followed for upgrade: https://github.com/justinfrench/formtastic/wiki/Upgrading-to-Formtastic-3.1

formtastic-bootstrap is upgraded for compatibility with current Formtastic.

Gemfile

@@ -52,7 +52,7 @@ gem 'uglifier', '>= 1.3.0'
 gem 'bootstrap-sass', '~> 3.3.4.1'
 gem 'autoprefixer-rails'
 gem 'formtastic-bootstrap'
-gem 'formtastic', '~> 2.3.0.rc3'
+gem 'formtastic', '~> 3.1.1'
 gem 'cocoon'
 
 # frontend javascripts

Gemfile.lock

@@ -166,10 +166,10 @@ GEM
     font-awesome-rails (4.1.0.0)
       railties (>= 3.2, < 5.0)
     formatador (0.2.4)
-    formtastic (2.3.0.rc3)
+    formtastic (3.1.3)
-      actionpack (>= 3.0)
+      actionpack (>= 3.2.13)
-    formtastic-bootstrap (3.0.0)
+    formtastic-bootstrap (3.1.1)
-      formtastic (>= 2.2)
+      formtastic (>= 3.0)
     geocoder (1.2.2)
     globalid (0.3.6)
       activesupport (>= 4.1.0)
@@ -504,7 +504,7 @@ DEPENDENCIES
   devise_ichain_authenticatable
   factory_girl_rails
   font-awesome-rails
-  formtastic (~> 2.3.0.rc3)
+  formtastic (~> 3.1.1)
   formtastic-bootstrap
   gravtastic
   guard-rspec (~> 4.2.8)

config/initializers/formtastic.rb

@@ -66,14 +66,48 @@ Formtastic::FormBuilder.required_string = proc { Formtastic::Util.html_safe(%{&n
 # specifying that class here.  Defaults to Formtastic::FormBuilder.
 # Formtastic::Helpers::FormHelper.builder = MyCustomBuilder
 
+# All formtastic forms have a class that indicates that they are just that. You
+# can change it to any class you want.
+# Formtastic::Helpers::FormHelper.default_form_class = 'formtastic'
+
+# Formtastic will infer a class name from the model, array, string ot symbol you pass to the
+# form builder. You can customize the way that class is presented by overriding
+# this proc.
+# Formtastic::Helpers::FormHelper.default_form_model_class_proc = proc { |model_class_name| model_class_name }
+
+# Allows to set a custom field_error_proc wrapper. By default this wrapper
+# is disabled since `formtastic` already adds an error class to the LI tag
+# containing the input.
+# Formtastic::Helpers::FormHelper.formtastic_field_error_proc = proc { |html_tag, instance_tag| html_tag }
+
 # You can opt-in to Formtastic's use of the HTML5 `required` attribute on `<input>`, `<select>`
-# and `<textarea>` tags by setting this to false (defaults to true).
+# and `<textarea>` tags by setting this to true (defaults to false).
-# Formtastic::FormBuilder.use_required_attribute = true
+# Formtastic::FormBuilder.use_required_attribute = false
 
 # You can opt-in to new HTML5 browser validations (for things like email and url inputs) by setting
-# this to false. Doing so will add a `novalidate` attribute to the `<form>` tag.
+# this to true. Doing so will add a `novalidate` attribute to the `<form>` tag.
 # See http://diveintohtml5.org/forms.html#validation for more info.
 Formtastic::FormBuilder.perform_browser_validations = true
 #
 Formtastic::Helpers::FormHelper.builder = FormtasticBootstrap::FormBuilder
 FormtasticBootstrap::FormBuilder.default_inline_hint_class = FormtasticBootstrap::FormBuilder.default_block_hint_class
+
+# By creating custom input class finder, you can change how input classes  are looked up.
+# For example you can make it to search for TextInputFilter instead of TextInput.
+# See # TODO: add link # for more information
+# NOTE: this behavior will be default from Formtastic 4.0
+Formtastic::FormBuilder.input_class_finder = Formtastic::InputClassFinder
+
+# Define custom namespaces in which to look up your Input classes. Default is
+# to look up in the global scope and in Formtastic::Inputs.
+# Formtastic::FormBuilder.input_namespaces = [ ::Object, ::MyInputsModule, ::Formtastic::Inputs ]
+
+# By creating custom action class finder, you can change how action classes are looked up.
+# For example you can make it to search for MyButtonAction instead of ButtonAction.
+# See # TODO: add link # for more information
+# NOTE: this behavior will be default from Formtastic 4.0
+Formtastic::FormBuilder.action_class_finder = Formtastic::ActionClassFinder
+
+# Define custom namespaces in which to look up your Action classes. Default is
+# to look up in the global scope and in Formtastic::Actions.
+# Formtastic::FormBuilder.action_namespaces = [ ::Object, ::MyActionsModule, ::Formtastic::Actions ]