Support for applying template to existing project

[gathuku]

closes #157

[gathuku]

@excid3 Please check this. Problems:

• Gem duplicate issues in case you apply to a project which already has this template gem present.

[andyw8]

Gem duplicate issues in case you apply to a project which already has this template gem present.

I think this should be resolved by a49f4f29f11cee913aa19c9f5b718a5b79a85506 ?

[gathuku]

@andyw8 Good work on solving gem duplicate issues.

[andyw8]

I think this would be fragile to run on an existing project, since there could be big variations in the existing code structure. Perhaps one approach could be to have an -i (--interactive) option which could prompt before each step to either to run it or skip it?

[gathuku]

@andyw8 that's true, the initial idea was to apply to a newly created project https://github.com/excid3/jumpstart/issues/157#issuecomment-947144028 But we can't escape the reality someone might want to apply in an old project.

[excid3]

I think you're both right on applying this to existing projects.