Fix search. Now it will only return a daemon pointer if it is live

[stew3254]

Fix Search of Unix systems. According to the docs for os.FindProcess(pid) this will never be nil even when I process doesn't exist.

On Unix systems, FindProcess always succeeds and returns a Process for the given pid, regardless of whether the process exists.

[codecov]

Codecov Report

Merging #72 (ddc0bfd) into master (bf83969) will decrease coverage by 1.53%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master      #72      +/-   ##
==========================================
- Coverage   15.89%   14.35%   -1.54%     
==========================================
  Files          10        8       -2     
  Lines         258      209      -49     
==========================================
- Hits           41       30      -11     
+ Misses        212      174      -38     
  Partials        5        5              

Impacted Files	Coverage Δ
daemon_unix.go	0.00% <0.00%> (ø)
lock_file.go	58.97% <0.00%> (-5.61%)	⬇️
lock_file_unix.go	75.00% <0.00%> (-5.00%)	⬇️
signal.go	7.14% <0.00%> (-2.39%)	⬇️
daemon.go	0.00% <0.00%> (ø)
command.go	0.00% <0.00%> (ø)
syscall_dup_pre17.go	0.00% <0.00%> (ø)
os_executable_pre18.go	0.00% <0.00%> (ø)
os_executable.go
... and 1 more

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[deniszh]

Looks legit - golang/go#34396