Parser add unRegister method

[dongasai]

Add the unRegister method to unRegister

I had a situation in development where I needed to unregister but _options was private so I couldn't unregister, so I added this.

[codecov-io]

Codecov Report

Merging #61 (e7757a2) into main (6b65506) will not change coverage.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##                main       #61   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
- Complexity       336       337    +1     
===========================================
  Files             16        16           
  Lines            827       830    +3     
===========================================
+ Hits             827       830    +3     

Impacted Files	Coverage Δ	Complexity Δ
src/Input/Parser.php	100.00% <100.00%> (ø)	36.00 <1.00> (+1.00)

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[adhocore]

for unset no need to check first with isset.

also multiple unset can be combined

eg: unset($a['key1'], $a['key2']);

[adhocore]

thank you very much. please try to get build pass somehow. 👏

[dongasai]

In the https://travis-ci.com/github/adhocore/php-cli/jobs/467713360 mission tasks fail because the configuration error

[adhocore]

thanks, instead of using unregister() method, can we rename it to unset()?

we have register() method with Parameter class as input arg which is not in line with unregister() method with string arg.

[dongasai]

@adhocore .