[easy] Remove unnecessary unwraps
[easy] Remove unnecessary unwraps

Try sytax [works on option](https://doc.rust-lang.org/edition-guide/rust-2018/error-handling-and-panics/the-question-mark-operator-for-easier-error-handling.html)

Remove 2x unwrap from testutils
Removing an unwrap from libra_swarm

Closes: #1115
Approved by: zamsden

aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra