v0.3.0 New Codebook

Completely changed the codebook function

It now makes heavy use of the officer and flextable packages to create a formatted Word document.

Bind freq_tables

Changed version from 0.2 to 0.2.1
Made freq_table easier to row bind.
Changed mean_table to follow the same variable name conventions.
Updated all vignettes and tests
Created unit tests for format_table