Fix indentation in list.rb
Remove (no description) printout.

It was basically just spamming and making things unreadable.
Since I'm changing the info command to only print out things that
actually have a description, this now only matters if the description
flag is set in user config.
Refactored empty list error to a constant

Changed (No tasks in list.) error message to a constant for multiple
uses.
Change info command to only print descriptions

Info command previously was just the task list printout with description
flag enabled, but now it only prints out tasks that actually have a
description to make things cleaner.
Also added some spacing in day.rb for readability, and redid some
spacing and function organization in list.rb
Added ending comment to user config section

When building single-file version, the user configuration section was
sitting right up next to the beginning of the code, so I added an ending
comment and some spacing.
Add index key colorization.
Added specific colorization for task names
Fix some spacing in list.rb
Refactor time difference calculation into a funct
Refactored switch() function

Switch function had three separate conditionals handling the three
different possible behaviors into an if/elsif/else to make it clear that
you can only have one of the three.
Grouped error checking in switch() together

Placed the two error conditionals into a chain together.
Also added some in-code documentation for switch() behavior.
Added TODO file and build folder to gitignore
Removed argument from calculate_time_difference
Handle printouts in s/m/h/d where appropriate.

When printing out completion for the day, or when switching tasks, we
feed it through the new convert_time() function which builds an
appropriate string.
Removed pry call from config.rb
Add vim description capturing

If you include EDITOR variable in the new_task args, it'll launch that
editor and capture the output for the description.
Update to 1.9.1