Add option k to test app cmd line, to specify keepalive timeout

[bill1600]

Update test app (libpd_test.c)
Add command line option 'k' to specify the keepalive timeout.

[codecov]

Codecov Report

Merging #44 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #44   +/-   ##
=======================================
  Coverage   62.44%   62.44%           
=======================================
  Files           3        3           
  Lines         639      639           
  Branches      131      131           
=======================================
  Hits          399      399           
  Misses        165      165           
  Partials       75       75

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[codecov]

Codecov Report

Merging #44 into master will decrease coverage by 0.48%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master      #44      +/-   ##
==========================================
- Coverage   62.44%   61.95%   -0.49%     
==========================================
  Files           3        3              
  Lines         639      644       +5     
  Branches      131      131              
==========================================
  Hits          399      399              
- Misses        165      170       +5     
  Partials       75       75

Impacted Files	Coverage Δ
src/libparodus.c	61.2% <0%> (-0.67%)	⬇️

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[codecov-io]

Codecov Report

Merging #44 into master will decrease coverage by 0.48%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master      #44      +/-   ##
==========================================
- Coverage   62.44%   61.95%   -0.49%     
==========================================
  Files           3        3              
  Lines         639      644       +5     
  Branches      131      131              
==========================================
  Hits          399      399              
- Misses        165      170       +5     
  Partials       75       75

Impacted Files	Coverage Δ
src/libparodus.c	61.2% <0%> (-0.67%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6701a5b...e3f632c. Read the comment docs.