changes Dict class instatiation with 'type' function

Removes the five lines of code that implement the Dict class;
Instantiates the equivalent class with the Python built-in functions 'type' and 'lambda';

Only creates+instantiates Dict when needed;
Module with less 3 lines of code (yey! :+1:);

Respects the 79 character line-width "rule" from PEP8;
Respects the usage of "'" instead of "\"" for strings;