Initialize start time for server

[hstejas]

By initializing start_time_ for server, I hope to measure the time taken to process a request at the end maybe in the set_logger callback and print it.

I only see current usage in client with server retaining the inital min value

[yhirose]

@hstejas thanks! Could you please add a unit test in test/test.cc?

[hstejas]

@hstejas thanks! Could you please add a unit test in test/test.cc?

Done, I have added a new "/custom" endpoint in the test fixture and member variable to store a callback. I think this will make newer tests easier.
Let me know if this is not okay, i can move the EXPECT_NE to "/hi"

[yhirose]

@hstejas almost! Could you please run clang-format to fix the style-check problem on Github Actions workflow?

[hstejas]

@hstejas almost! Could you please run clang-format to fix the style-check problem on Github Actions workflow?

Done

[yhirose]

@hstejas thanks for your contribution!