move interpreter detection to package.yml

[jhheider]

Goes with your app.exec.ts rewrite, @mxcl.

Requires https://github.com/teaxyz/pantry.core/pull/33

[what-the-diff[bot]]

• Added an Interpreter interface
• Changed the unshift function to take in a new argument of type Interpreter instead of two strings (project and args)
• Created getInterpreter which returns undefined if no interpreter is found for that extension, or else it returns an object with project and args properties
• In exec(), we call usePantry().getInterpreter() on the file's extension, then pass its return value into unshift() as long as it isn't undefined

[jhheider]

Can't pass checks (fails tea -x setup.py) until pantry is merged.

[mxcl]

wonderful.

[mxcl]

rewrite complete

[mxcl]

lets add a test.

edit: probs this will do https://github.com/teaxyz/cli/pull/200