add release optimization options

[Fogapod]

a test to see how much it changes CI compile time

[Fogapod]

This did not affect build time (unless i did something wrong) but might improve performance in release mode

[Alainx277]

Do you have any kind of record of how the performance changed? (ex. FPS, server cpu usage)

[Fogapod]

at least for #26 adding these 2 options results in huge boost 😄

[Fogapod]

Added strip option as well. It decreases executable size significantly.

Docker build times comparisons on local machine (includes downloading git and crates.io files on my slow internet):

Without release options:
strip = false
Finished release [optimized] target(s) in 2m 45s - first stage
Finished release [optimized] target(s) in 1m 28s - second stage
Exucutable: 36.2M

With release options:
strip = true
Finished release [optimized] target(s) in 2m 20s - first stage
Finished release [optimized] target(s) in 3m 50s - second stage
Exucutable: 17.2M

With release options:
strip = "debuginfo"
Finished release [optimized] target(s) in 2m 08s - first stage
Finished release [optimized] target(s) in 3m 52s - second stage
Executable: 21.0M