ES: fixed bug in snippet indexing

app/models/personal_snippet.rb

@@ -16,4 +16,7 @@
 #
 
 class PersonalSnippet < Snippet
+  # Elastic search configuration (it does not support STI)
+  document_type 'snippet'
+  index_name [Rails.application.class.parent_name.downcase, 'snippet', Rails.env].join('-')
 end

app/models/project_snippet.rb

@@ -16,6 +16,10 @@
 #
 
 class ProjectSnippet < Snippet
+  # Elastic search configuration (it does not support STI)
+  document_type 'snippet'
+  index_name [Rails.application.class.parent_name.downcase, 'snippet', Rails.env].join('-')
+
   belongs_to :project
   belongs_to :author, class_name: "User"