Persistent Incremental Counter based on a counter file.
>>> from incremental_counter import Counter
>>> c = Counter("/tmp/counter.txt")
>>> c.current()
0
>>> c.inc()
1
>>> c.inc()
2
>>> c.reset()
0
>>> c.set(3)
3
>>> c.dec()
2
>>> c.dec()
1
>>> c.dec()
0
>>> c.dec()
0
>>> c.dec()
0
- 0.1.1 2018.11.03 first version
- 0.1.3 2018.11.07 remove redundant class