Define Dotenv::Railtie.load
Rename "dotenv/railtie" to "dotenv/rails"
Add dotenv/rails-now to load dotenv immediately
Note load order considerations in REAME
Update change log with `Dotenv::Railtie.load` and `dotenv/rails-now`
Exclude rails files from dotenv gem
Override .load class method to avoid calling Kernel#load
Merge pull request #142 from bkeepers/load-on-railtie

Provide options for loading dotenv-rails earlier in the bootstrap process