Feature: Split Deployer class

The `Deployer` class is a little big at the moment and it is expected to grow. This will eventually lead to messy code and thats what we are trying to avoid. A solution to this would be to split the class into multiple classes. This is also a great way to get a little more abstraction into the code base.

This is what I imagined:
- Create some sort of task interface with some sort of `run` method
- `execSsh` and `execCommands` will be moved into their respective classes which implement the task interface
- Create instances of the task classes in the `Deployer` class and call them when needed

I think this would greatly improve the code. If you have any other solution idea please let me know!

Please comment if you would like to work on this.