add logs tests and go mod tidy

[caixw]

go test -cpu=1,2,4 -benchmem -benchtime=5s -bench "Logs.*"
goos: darwin
goarch: amd64
pkg: github.com/imkira/go-loggers-bench
cpu: Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz
BenchmarkLogsTextPositive     	15071587	       405.5 ns/op	     184 B/op	       4 allocs/op
BenchmarkLogsTextPositive-2   	15068866	       392.1 ns/op	     184 B/op	       4 allocs/op
BenchmarkLogsTextPositive-4   	10853109	       546.2 ns/op	     184 B/op	       4 allocs/op
BenchmarkLogsTextNegative     	207347248	        28.92 ns/op	       0 B/op	       0 allocs/op
BenchmarkLogsTextNegative-2   	432201258	        13.27 ns/op	       0 B/op	       0 allocs/op
BenchmarkLogsTextNegative-4   	530426706	         9.743 ns/op	       0 B/op	       0 allocs/op
BenchmarkLogsJSONNegative     	90371790	        61.54 ns/op	      16 B/op	       1 allocs/op
BenchmarkLogsJSONNegative-2   	171595904	        38.12 ns/op	      16 B/op	       1 allocs/op
BenchmarkLogsJSONNegative-4   	156709440	        42.18 ns/op	      16 B/op	       1 allocs/op
BenchmarkLogsJSONPositive     	 4583920	      1300 ns/op	     512 B/op	      11 allocs/op
BenchmarkLogsJSONPositive-2   	 4026618	      1471 ns/op	     512 B/op	      11 allocs/op
BenchmarkLogsJSONPositive-4   	 3898501	      1528 ns/op	     512 B/op	      11 allocs/op
PASS
ok  	github.com/imkira/go-loggers-bench	90.687s