Improve binstub generation with output

[paracycle]

Motivation

We haven't been showing any output for binstub generation.

Implementation

Add output that bin/tapioca was created or force created depending the existence of bin/tapioca

Tests

Updated tests to check for the bin/tapioca output. Also changed test to run bundle exec tapioca and not bundle exec bin/tapioca since (a) we cannot rely on the binstub existing and (b) if running the binstub, it is meaningless to prepend a bundle exec to it.

[mutecipher]

Good catch