Add get_tree to base.
WIP get emails
More WIP
[+MG] remove references to list and recipients
[+MG] refactor HTTParty out into its own class

- it does not need to be part of the base object
[+MG] extract email centre tree object in its own class and now in the base.
associated spec improvements.
[+MG] remove old style configuration as all parts now using yml based config file
[+MG] remove base class as its not that complicated
[+MG] move email and template into trees namespace, replace specs with those that add value.
[+MG] upgrade rspec version
[+MG] return error class from http validator
[+MG] ensure object attributes can not be modified
[+MG] WIP: tidy up email and template classes
[+MG] rename email to node
[+MG] move fake web out to separate files, small refactor of node methods.
[+MG] enabled email triggering.
[+MG] deal with timeouts better.
[+MG] small refactor and final tidy. Better errors for node methods.
[+MG] add example config file
[+MG] rename trees to nodes and contained classes based on tree root