cleanup and remove unused steps

@kevgo 
I'm seriously detail-nitpicking here. I have seen the style with braces mostly used for simple functional-programming type constructs like

```ruby
input.each { &:strip }
```
If you provide a block to run later or separately, as part of sandwich code like here, the `do` expresses that often better:

```ruby
at_path(path) do
  run "git checkout #{branch_name}"
end
```