Added underscore prefix for unused local parameteres as per the ruby style guide https://github.com/bbatsov/ruby-style-guide/blob/master/README.md#underscore-unused-vars
Fix #get_more for query_cache with large collection
Rephrase comment in lib/mongoid/railtie.rb
remove Railtie.generator

This method is no longer needed, he detects the generator method wich has changed from Rails 2.x to 3.0.0. Mongoid has a dependency to activemodel > 4.0, which related in a dependency to Rails > 4.0. Which means that this check is no longer needed, there can't be a Rails < 4.0
Merge pull request #3867 from timoschilling/patch-3

remove Railtie.generator
Merge pull request #3857 from Zorbash/master

Rephrase comment in lib/mongoid/railtie.rb
Merge pull request #3841 from lethalbrains/master

Added underscore prefix for unused local parameters as per the ruby sty...
Change spec order to make it green again

Not sure why, but after 2945bc58b1fef5433b500d9a44bae484022679c8 the spec added to attributes_spec.rb made criteria_spec start failing, that only happens when running the entire test suite and under MRI
AM, AP bump on Gemfile
Use AM 4.2 rc
Remove guard and guard-rspec from dev env
Bump ruby version
Bump rspec to 3.1.x
Update changelog for #3847
Merge pull request #3847 from cheredon/issue3847

Pluck duplicates first 101 records for query cache
Organize changelog [skip ci]
Improve query_cache specs
Improve travis file

mainly add sudo false, which should speed up the jobs
Fix calls to #id instead of #_id
Add #id custom alias tests