update client exception

[maximzasorin]

• Added type hint for $request and $response
• Made $response optional, as in Guzzle's RequestException
• Added passing exception code, so we can use it:

  try {
      $shopManager->get();
  } catch (ClientException $exception) {
      if ($exception->getCode() == 401) {
          // Unauthorized request
      }
  }

[codecov[bot]]

Codecov Report

Merging #51 into master will increase coverage by 0.11%. The diff coverage is 100%.

@@             Coverage Diff              @@
##             master      #51      +/-   ##
============================================
+ Coverage     88.15%   88.27%   +0.11%     
  Complexity     1371     1371              
============================================
  Files           100      100              
  Lines          3377     3377              
============================================
+ Hits           2977     2981       +4     
+ Misses          400      396       -4

Impacted Files	Coverage Δ	Complexity Δ
src/Client.php	94.11% <ø> (ø)	31 <0> (ø)	:arrow_down:
src/Exception/ClientException.php	50% <100%> (+50%)	3 <1> (ø)	:arrow_down:

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