Advice to read the upgrade guide
Changed directory check to -d
Add `run_locally` example to README
Comment out `ask` example in template

This resolves issues #524 by making the `ask` example opt-in
Add `sudo` dsl method

Example usage:

    on roles :all do
      sudo :mkdir, '-pv', shared_path, releases_path
    end
include installation integration tests in main suite run
Implement `--dry-run` option

By passing `--dry-run` or `-n`, Capistrano will configure `SSHKit` to
use the `Printer` backend.

Usage:

    cap production deploy --dry-run
Implement `lock` feature

Ensure a Capistrano version by including a `lock` directive in your
Capfile:

  lock '~> 3.0.0'

An error will be raised if the loaded version of Capistrano does not
meet the dependency specified.
Preparing Release v3.0.0.pre14