Updated CHANGELOG for Core/pull/84
Merge pull request #1995 from neonichu/master

Updated CHANGELOG for Core/pull/84
[UI] Always load to ensure proper override of CoreUI
Release 0.31.1
Ignore .idea directory created by JetBrains IDEs, e.g. RubyMine
Added basic Update command prototype
Refactoring: Renamed Installer#update_mode to Installer#update
Changed signature doc of Pod::Project#run_install_with_update and call it appropriately by Pod::Project::Update#run
Refactoring: Replaced Installer::Analyzer's getter and setter update_mode by #update, #update= and #update_mode?
Refactored checks for update_mode? by allowing different states through symbols with update_mode
Implemented update_mode == :selected
Ignore RVM files
Ignore Bundler temporary files
++cocoapods-integration-specs and mirror changes in spec/integration
Implemented integration test for update_selected
Changed spec as `pod update` falls back to `pod install` if no Lockfile is present

Because it improves the user convenience and bundler does it the same way.
Allow to specify which functional spec should be run by rake argument

e.g. rake 'spec:functional[command/project]'
The single quotes are needed for zsh.
Added a functional spec for telling the user that the Pods cannot be updated unless they are installed
Implemented check if all requested Pods are installed
Improved CLI description of Command::Update