Added provider parameter to find_resource (#998)

Allow other providers than email in registration

Author: m4-miranda

app/controllers/devise_token_auth/concerns/resource_finder.rb

@@ -15,7 +15,6 @@ def get_case_insensitive_field_from_resource_params(field)
   def find_resource(field, value)
     # fix for mysql default case insensitivity
     q = "#{field.to_s} = ? AND provider='#{provider.to_s}'"
-
     if ActiveRecord::Base.connection.adapter_name.downcase.starts_with? 'mysql'
       q = "BINARY " + q
     end

app/controllers/devise_token_auth/registrations_controller.rb

@@ -7,7 +7,7 @@ class RegistrationsController < DeviseTokenAuth::ApplicationController
 
     def create
       @resource            = resource_class.new(sign_up_params)
-      @resource.provider   = "email"
+      @resource.provider   = provider
 
       # honor devise configuration for case_insensitive_keys
       if resource_class.case_insensitive_keys.include?(:email)