Added Quantities model and controller

commands:
rails generate redmine_plugin_model body_tracking quantity
rails generate redmine_plugin_controller body_tracking quantities index
create destroy

app/controllers/quantities_controller.rb

@@ -0,0 +1,11 @@
+class QuantitiesController < ApplicationController
+
+  def index
+  end
+
+  def create
+  end
+
+  def destroy
+  end
+end

app/helpers/quantities_helper.rb

@@ -0,0 +1,2 @@
+module QuantitiesHelper
+end

app/models/quantity.rb

@@ -0,0 +1,2 @@
+class Quantity < ActiveRecord::Base
+end

app/views/quantities/create.html.erb

@@ -0,0 +1 @@
+<h2>QuantitiesController#create</h2>

app/views/quantities/destroy.html.erb

@@ -0,0 +1 @@
+<h2>QuantitiesController#destroy</h2>

app/views/quantities/index.html.erb

@@ -0,0 +1 @@
+<h2>QuantitiesController#index</h2>