Changed from deprecated crate gcc-rs to cc-rs

[Candunc]

All tests pass as well:

running 121 tests
[...]
test result: ok. 121 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

running 243 tests
[...]
test result: ok. 243 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

running 4 tests
[...]
test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

running 5 tests
test src\int.rs - int::Int (line 60) ... ok
test src\int.rs - int::Int (line 103) ... ok
test src\int.rs - int::Int (line 67) ... ok
test src\int.rs - int::Int (line 80) ... ok
test src\int.rs - int::RandomInt (line 3664) ... ok

test result: ok. 5 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

[rozbb]

I'm very sorry for taking so long. This was just done in 45c394. Thank you for your contribution!