Initial work on install task.

I added Thor to the project and am using it to create a series of generator tasks which will be used to install Topographer in a project.  These tasks will create the imports scaffold that can then be used to construct mappings and various import strategies.
Finish generator

Added remaining templates and tasks to the install Thor task.  This task can be invoked after installing the Topographer gem by running `thor topographer:install` in your project root folder.  If you want to install mapping templates for any models, please specify them using the `--models` option followed by a space delimited list of models to generate templates for.
Make UserInterfaceImport transactional

Make the generated UserInterfaceImport transactional by default so that records will not be imported when errors occur.
Improve Readme
Update version