Handle errors by stopping execution

Hello again :)

I came across a case that I think could be improved (unless I missed something and it is already present). Here was the output from my console when running `clojure-control` :

```
localhost:ssh: cd /var/dev/my-repo/ ; git clone git@github.com:nha/my-repo.git
localhost:stderr: zsh:cd:1: no such file or directory: /var/dev/my-repo/
Cloning into 'my-repo'...
localhost:exit: 0
```

As you can see, the `cd` command failed because the directory didn't exist.
And then the `clone` command fired up anyway.
So the clone ended up in my home repository.

I can see two possible solutions :
- replace the ";" delimiter with a "&&" delimiter. This is probably a quick-fix, and it relies on commands to return standard success/error codes.
- set bash flags for the duration of the command :

set -o errexit
set -o pipefail
set -o nounset

What do you think ?

Thank you for making this library.

Start by reproducing the reported clojure-control command involving `cd` followed by `git clone`, then trace where shell command execution handles the failed `cd`. Done means a failed command prevents the following command from running, with behavior verified for this case.

Written by the indexing model from the issue text.