Add shell support to fake_server

[pkittenis]

To test shell specific behaviour like PTYs, daemon processes and the like, fake_server would need shell support and to run shell commands for real.

Add shell support to fake_server and add tests for PTY use and daemon processes. Related to #23

[pkittenis]

Resolved in master branch. Fake server now renamed to embedded server and is a functional ssh server that actually runs shell commands.

Tests have been updated to run bash commands and already have identified an issue - #37 - from them.