Gemfile.lock updated for Paperclip 3.4.1

* since Gemfile.lock is checked in, seems like it wants to be updated following the 3.4.1 release?
Uses secure RubyGems URL
Changed deprecated constant in documentation

Changed Spec::Runner to RSpec.
Merge pull request #1177 from evendis/gemfile.lock_update

Gemfile.lock updated for Paperclip 3.4.1
Merge pull request #1181 from mrzasa/master

Changed Spec::Runner to RSpec.
Merge pull request #1179 from pmcconnell/patch-1

Uses secure RubyGems URL
Removes some confusion from ContenTypeDetector methods
Fixes a test that caused an error in Ruby 2.0.0
https in the Gemfile.lock
add -layers 'optimize' flag to animated gif convert cmds
animated gif option formatting
fix tests from animated gif layers optimize change
Clarify tests for frame dimensions
Add ruby-2.0.0 to travis CI