Tweak runtime dependencies(activerecord and activesupport)

Supports security fix of Rails v4.1.1

ref: [Rails 3.2.18, 4.0.5 and 4.1.1 have been released!](http://weblog.rubyonrails.org/2014/5/6/Rails_3_2_18_4_0_5_and_4_1_1_have_been_released/)

:bow: :bow: :bow: