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
Merge pull request #592 from capistrano/feature/dry-run

Implement `--dry-run` option
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.
Merge pull request #593 from capistrano/feature/lock

Implement `lock` feature
Merge pull request #1 from capistrano/v3

Merge from capistrano head