Fixed errors when clf.yaml is empty

Removed unnecessary requests

Snippets can be saved locally

Updated README.rst

Browse the snippets by default (removed --browse argument)

Added the --id argument

Added the n arguments to limit the snippets results

Updated version (0.5.6 -> 0.5.7)

Merge pull request #9 from Xuefeng-Zhu/patch-4

Handle the case response is not json

Updated version (0.5.5 -> 0.5.6)

Removed unnecessary newline

Merge pull request #8 from Xuefeng-Zhu/patch-3

Deal with case no result is returned

Updated version (0.5.4 -> 0.5.5)