solutions for leetcode quesitons in rust.

Here are the purpose of this project:

1. be able to run the solution of the leetcode problems
2. be able to print the performance data.
3. be able to run the test cases.
4. be able to run unit test
5. be able to run specified solution by using the command line arguments.

here are the thought I can think of so far, update this when I have more ideas.