Import feature for following/blocking lists (addresses #62, #177, #201, #454)

spec/fabricators/import_fabricator.rb

@@ -0,0 +1,2 @@
+Fabricator(:import) do
+end

spec/models/import_spec.rb

@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe Import, type: :model do
+
+end