Welcome _convertUnitAsWords

Removed 2 useless import statements.
Added two big, dumb, ugly, hardcoded (and maybe misplaced?)
dictionaries.
Whoever finds a better alternative will get my :+1:.

Implemented _convertUnitAsWords and added a test script for it.

Can someone tell me if it is a bad practice to write an iterable and
perform tests by iterating over it?

Deleted some blank lines and whitespaces that bothered me.