Fix many typos in cluster.cc

[git-hulk]

1. Fix typos in the cluster.cc
2. Use const string when appearing many times
3. Fix incorrect sleep time in rwlock test case

Close #873

[PragmaTwice]

I notice that CI is down in darwin clang. Maybe #include <chrono> is needed to use namespace std::chrono_literals.

[git-hulk]

I notice that CI is down in darwin clang. Maybe #include <chrono> is needed to use namespace std::chrono_literals.

Yes, should include <chrono>, fixed.

[git-hulk]

hi @PragmaTwice, seems the namespace of chrono_literals is a bit different between compilers, do you suggest rollbacking to use the previous way?

[PragmaTwice]

hi @PragmaTwice, seems the namespace of chrono_literals is a bit different between compilers, do you suggest rollbacking to use the previous way?

Sure. Maybe it need c++14 🤣

[git-hulk]

hi @PragmaTwice, seems the namespace of chrono_literals is a bit different between compilers, do you suggest rollbacking to use the previous way?

Sure. Maybe it need c++14 🤣

I was a bit confuse when looking its docs, it says std::literals::chrono_literals required at least C++14, but std::chrono_literals can be found in C++11's chrono. Let's use the legacy way first.

[git-hulk]

Thanks all, merging...