add `enable-checkpoint` command-line switch

[gorilla001]

• 添加了开启mesos checkpoint的开关

  参数：SWAN_ENABLE_CHECK_POINT --enable-checkpoint 默认值：false

[codecov[bot]]

Codecov Report

Merging #907 into master will not change coverage. The diff coverage is n/a.

@@          Coverage Diff           @@
##           master    #907   +/-   ##
======================================
  Coverage    5.65%   5.65%           
======================================
  Files          21      21           
  Lines        2830    2830           
======================================
  Hits          160     160           
  Misses       2668    2668           
  Partials        2       2

[bbklab]

LGTM

[bbklab]

ping @pangzheng