Add `--cpus` options to a container

[gabrielsvinha]

Changes the class HostConfig to receive the property cpus when creating a new container.

Add unit test to the specified parameters.

Solves #959

[codecov-io]

Codecov Report

Merging #1034 into master will not change coverage. The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1034   +/-   ##
=========================================
  Coverage     67.39%   67.39%           
  Complexity      774      774           
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  Files           176      176           
  Lines          3233     3233           
  Branches        367      367           
=========================================
  Hits           2179     2179           
  Misses          897      897           
  Partials        157      157

[davidxia]

@GabrielSVinha just wondering about the above.

[rwmajor2]

Can someone comment on this? There is a CpuCount, but is it really Windows only? It's located under the HostConfig.