Created Unit model

command: rails generate redmine_plugin_model body_tracking unit
name:string shortname:string type:integer

db/migrate/001_create_units.rb

@@ -0,0 +1,9 @@
+class CreateUnits < ActiveRecord::Migration
+  def change
+    create_table :units do |t|
+      t.string :name
+      t.string :shortname
+      t.integer :type
+    end
+  end
+end