Potential bug fix

Select first element from the fetchone() method at once.
Empty setupfile
Consistency and PEP8
Setup tests in main_test.py

Need to refactor some files
Refactor into easier to read parts
Add docopt library
Made snapshot.set() method operate relative to CWD

Before it was relative to ~/.rab
Implemented docopt

Usage:
    rab snapshot create PATH...
    rab snapshot delete PATH...
    rab snapshot <name> add PATH...
    rab snapshot <name> reconstruct <file> PATH
    rab blocks delete
    rab (--version | -h | --help)

Options:
    -h --help  Show this help message and quit.
    --version  Show version.
New todos in README
Better way to map functions to args

Nested ifs just don't cut it
New todos in README
Implemented logger and replaced print statments
Better way to map functions to args

Nested ifs just don't cut it
General refactoring

Use iter instead of while True
Fix main method to take no args