add test_game stress test

[xiaonanln]

[codecov[bot]]

Codecov Report

Merging #102 into master will decrease coverage by 1.67%. The diff coverage is 4.65%.

@@            Coverage Diff             @@
##           master     #102      +/-   ##
==========================================
- Coverage   34.22%   32.54%   -1.68%     
==========================================
  Files          41       37       -4     
  Lines        3708     3220     -488     
==========================================
- Hits         1269     1048     -221     
+ Misses       2277     2050     -227     
+ Partials      162      122      -40     

Impacted Files	Coverage Δ
engine/entity/Space.go	0.00% <ø> (ø)
engine/kvdb/kvdb.go	37.11% <ø> (+2.79%)	:arrow_up:
engine/netutil/Connection.go	0.00% <0.00%> (-100.00%)	:arrow_down:
engine/netutil/MessagePackMsgPacker.go	81.81% <ø> (ø)
engine/netutil/Packet.go	0.00% <0.00%> (-22.57%)	:arrow_down:
engine/netutil/PacketConnection.go	0.00% <0.00%> (-51.12%)	:arrow_down:
engine/netutil/netutil.go	0.00% <ø> (ø)
engine/config/read_config.go	69.36% <100.00%> (+5.80%)	:arrow_up:
engine/netutil/TCPServer.go	24.00% <0.00%> (-8.00%)	:arrow_down:
... and 3 more

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