feat(livenil): add binary livenil

[a-wing]

LiveNil only develop mode and test mode
Remove liveman --features=liveion

Before:

cargo run --bin=liveman --features=liveion

After:

cargo run --bin=livenil -- -c conf/livenil

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 47 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/livenil.rs	0.00%	46 Missing ⚠️
liveman/src/lib.rs	0.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
liveman/src/store.rs	0.00% <ø> (ø)
liveman/src/lib.rs	0.00% <0.00%> (ø)
src/livenil.rs	0.00% <0.00%> (ø)

... and 1 file with indirect coverage changes