Fix number key handled properlyfix path parsing logicupdate documentationupdate test cases (including edge cases)
Fix number key handled properly
Treat Number Keys as Valid Keys in the set Function
Fix#446 Treat Number Keys as Valid Keys in the set Function
fix path parsing logic
whichever we use 
set({}, ‘a.0.b’, 3), set({}, ‘a[0].b’ ,3), set({}, ‘a.[0].b’, 3), number key always has been treated as index number of array.but there are many cases that we may use number as a key in object like 
userId, productId etc.so I updated the 
path parsing logic with considering edge cases.
update documentation

add example to show how to handle number key in object.
so that people can use and understand properly.
update test cases (including edge cases)
