Igor (major rewrite)

As a tool that helps you run experiments, 
This introduces a major rewrite of the experiments infrastructure. It still relies on `experiments.rb` for some functionality, but is mostly a full rewrite which resides in `igor.rb`

## New features
- New Ruby DSL syntax for files
- Experiments submitted as batch jobs so they do their own writing to the SQLite database
- "Interactive" mode based on the DSL syntax and Pry's REPL
- Rebranding as "Igor" ("Lab Assistant")
- Object-oriented design

### Currently missing features