[bestpath_selection]: add testcase for table.go
[bestpath_selection]: add testcase for table.go

a16/gobgp,h-naoto/gobgp,osrg/gobgp,postfix/gobgp,fujita/gobgp,osrg/gobgp,fujita/gobgp,a16/gobgp,j-kato/gobgp,ramrunner/gobgp,postfix/gobgp,h-naoto/gobgp,a16/gobgp,YujiOshima/gobgp,ishidawataru/gobgp,j-kato/gobgp,osrg/gobgp,j-kato/gobgp,tamihiro/gobgp,h-naoto/gobgp,ishidawataru/gobgp,Dipsingh/gobgp,tamihiro/gobgp,a16/gobgp,a16/gobgp,YujiOshima/gobgp,tamihiro/gobgp,Dipsingh/gobgp,osrg/gobgp,fujita/gobgp,ishidawataru/gobgp,a16/gobgp,Dipsingh/gobgp,ramrunner/gobgp,a16/gobgp,fujita/gobgp,tamihiro/gobgp,postfix/gobgp,YujiOshima/gobgp,ramrunner/gobgp