Adding a block model and filter mentions from blocked users (fix #60)

db/migrate/20161003145426_create_blocks.rb

@@ -0,0 +1,12 @@
+class CreateBlocks < ActiveRecord::Migration[5.0]
+  def change
+    create_table :blocks do |t|
+      t.integer :account_id, null: false
+      t.integer :target_account_id, null: false
+
+      t.timestamps null: false
+    end
+
+    add_index :blocks, [:account_id, :target_account_id], unique: true
+  end
+end