Depend on any version of spree_core 2.1
Bump to active_shipping 0.11.0

Fixes #136
rate calculations per package not by order
added some helper functions as well to cleanup some of the code
also made sure the weight tests where using packages instead
of orders and that they still made sense

Conflicts:
	spec/models/weight_limits_spec.rb
fix spree version dependency
Merge pull request #141 from mrpollo/fix_gemfile_spree_version

fix gemfile spree version on 2-1-stable branch
Merge branch '2-1-stable' into calculate_rates_per_package_2_1_stable

* 2-1-stable:
  fix spree version dependency
Merge pull request #142 from mrpollo/calculate_rates_per_package_2_1_stable

Calculate rates per package
Don't re-draw admin/product routes
use custom routes mapper
use new custom route mapper append_routes