Hide error for failed install of optional cover tool.
Hide error for failed install of optional cover tool.

It is mostly only installed for use in Travis. Other users can install
it as root if they are interested in running coverage.

Fixes #358

dumbunny/vitess,vitessio/vitess,cloudbearings/vitess,tirsen/vitess,anusornc/vitess,tinyspeck/vitess,mlc0202/vitess,HubSpot/vitess,cloudbearings/vitess,fengshao0907/vitess,atyenoria/vitess,HubSpot/vitess,vitessio/vitess,yaoshengzhe/vitess,AndyDiamondstein/vitess,mattharden/vitess,SDHM/vitess,vitessio/vitess,dumbunny/vitess,applift/vitess,cgvarela/vitess,enisoc/vitess,SDHM/vitess,guokeno0/vitess,aaijazi/vitess,anusornc/vitess,michael-berlin/vitess,erzel/vitess,SDHM/vitess,AndyDiamondstein/vitess,mapbased/vitess,cgvarela/vitess,nurblieh/vitess,mlc0202/vitess,applift/vitess,fengshao0907/vitess,mattharden/vitess,atyenoria/vitess,dcadevil/vitess,AndyDiamondstein/vitess,cloudbearings/vitess,nurblieh/vitess,ptomasroos/vitess,kuipertan/vitess,HubSpot/vitess,mapbased/vitess,xgwubin/vitess,guokeno0/vitess,tjyang/vitess,tjyang/vitess,applift/vitess,tirsen/vitess,mattharden/vitess,cloudbearings/vitess,kmiku7/vitess-annotated,cloudbearings/vitess,guokeno0/vitess,netroby/vitess,ptomasroos/vitess,enisoc/vitess,nurblieh/vitess,rnavarro/vitess,cgvarela/vitess,pivanof/vitess,michael-berlin/vitess,ptomasroos/vitess,kuipertan/vitess,mlc0202/vitess,dumbunny/vitess,pivanof/vitess,pivanof/vitess,yaoshengzhe/vitess,kuipertan/vitess,aaijazi/vitess,mattharden/vitess,anusornc/vitess,kmiku7/vitess-annotated,SDHM/vitess,skyportsystems/vitess,davygeek/vitess,alainjobart/vitess,anusornc/vitess,michael-berlin/vitess,erzel/vitess,dcadevil/vitess,mahak/vitess,atyenoria/vitess,aaijazi/vitess,davygeek/vitess,erzel/vitess,kuipertan/vitess,dumbunny/vitess,yangzhongj/vitess,michael-berlin/vitess,guokeno0/vitess,kmiku7/vitess-annotated,pivanof/vitess,yangzhongj/vitess,alainjobart/vitess,sougou/vitess,erzel/vitess,xgwubin/vitess,davygeek/vitess,rnavarro/vitess,michael-berlin/vitess,kmiku7/vitess-annotated,mapbased/vitess,applift/vitess,mapbased/vitess,ptomasroos/vitess,netroby/vitess,aaijazi/vitess,tjyang/vitess,fengshao0907/vitess,davygeek/vitess,vitessio/vitess,yangzhongj/vitess,mlc0202/vitess,rnavarro/vitess,dcadevil/vitess,applift/vitess,pivanof/vitess,anusornc/vitess,tirsen/vitess,tirsen/vitess,atyenoria/vitess,guokeno0/vitess,davygeek/vitess,HubSpot/vitess,sougou/vitess,kmiku7/vitess-annotated,skyportsystems/vitess,applift/vitess,alainjobart/vitess,tinyspeck/vitess,nurblieh/vitess,xgwubin/vitess,yaoshengzhe/vitess,xgwubin/vitess,tjyang/vitess,yangzhongj/vitess,fengshao0907/vitess,kmiku7/vitess-annotated,applift/vitess,xgwubin/vitess,guokeno0/vitess,rnavarro/vitess,pivanof/vitess,yaoshengzhe/vitess,atyenoria/vitess,SDHM/vitess,AndyDiamondstein/vitess,HubSpot/vitess,netroby/vitess,enisoc/vitess,sougou/vitess,michael-berlin/vitess,mahak/vitess,skyportsystems/vitess,sougou/vitess,pivanof/vitess,tjyang/vitess,michael-berlin/vitess,nurblieh/vitess,anusornc/vitess,dumbunny/vitess,enisoc/vitess,mlc0202/vitess,AndyDiamondstein/vitess,cgvarela/vitess,kuipertan/vitess,kuipertan/vitess,rnavarro/vitess,dumbunny/vitess,kmiku7/vitess-annotated,kmiku7/vitess-annotated,netroby/vitess,ptomasroos/vitess,xgwubin/vitess,HubSpot/vitess,dcadevil/vitess,kuipertan/vitess,netroby/vitess,AndyDiamondstein/vitess,nurblieh/vitess,mahak/vitess,rnavarro/vitess,enisoc/vitess,tirsen/vitess,cloudbearings/vitess,cgvarela/vitess,dumbunny/vitess,yangzhongj/vitess,dcadevil/vitess,AndyDiamondstein/vitess,ptomasroos/vitess,vitessio/vitess,skyportsystems/vitess,skyportsystems/vitess,mattharden/vitess,SDHM/vitess,nurblieh/vitess,skyportsystems/vitess,erzel/vitess,fengshao0907/vitess,applift/vitess,tinyspeck/vitess,sougou/vitess,mapbased/vitess,rnavarro/vitess,yaoshengzhe/vitess,aaijazi/vitess,tirsen/vitess,mapbased/vitess,tinyspeck/vitess,dcadevil/vitess,yaoshengzhe/vitess,netroby/vitess,nurblieh/vitess,sougou/vitess,vitessio/vitess,yangzhongj/vitess,atyenoria/vitess,alainjobart/vitess,fengshao0907/vitess,mlc0202/vitess,erzel/vitess,kuipertan/vitess,applift/vitess,mapbased/vitess,AndyDiamondstein/vitess,fengshao0907/vitess,michael-berlin/vitess,vitessio/vitess,mattharden/vitess,fengshao0907/vitess,atyenoria/vitess,xgwubin/vitess,erzel/vitess,pivanof/vitess,yangzhongj/vitess,michael-berlin/vitess,alainjobart/vitess,yangzhongj/vitess,enisoc/vitess,mattharden/vitess,HubSpot/vitess,erzel/vitess,ptomasroos/vitess,sougou/vitess,mattharden/vitess,mapbased/vitess,dcadevil/vitess,netroby/vitess,anusornc/vitess,mahak/vitess,tirsen/vitess,tinyspeck/vitess,anusornc/vitess,cloudbearings/vitess,yaoshengzhe/vitess,xgwubin/vitess,nurblieh/vitess,mahak/vitess,kmiku7/vitess-annotated,AndyDiamondstein/vitess,ptomasroos/vitess,tjyang/vitess,netroby/vitess,dumbunny/vitess,skyportsystems/vitess,mlc0202/vitess,pivanof/vitess,cgvarela/vitess,guokeno0/vitess,davygeek/vitess,atyenoria/vitess,aaijazi/vitess,cloudbearings/vitess,atyenoria/vitess,SDHM/vitess,tjyang/vitess,tjyang/vitess,HubSpot/vitess,rnavarro/vitess,mattharden/vitess,mapbased/vitess,dumbunny/vitess,mlc0202/vitess,skyportsystems/vitess,ptomasroos/vitess,cgvarela/vitess,tinyspeck/vitess,erzel/vitess,mahak/vitess,aaijazi/vitess,xgwubin/vitess,aaijazi/vitess,erzel/vitess,rnavarro/vitess,yangzhongj/vitess,aaijazi/vitess,cgvarela/vitess,yaoshengzhe/vitess,tinyspeck/vitess,tirsen/vitess,guokeno0/vitess,SDHM/vitess,applift/vitess,tjyang/vitess,alainjobart/vitess,mahak/vitess,cgvarela/vitess,kuipertan/vitess,guokeno0/vitess,alainjobart/vitess,tirsen/vitess,netroby/vitess,SDHM/vitess,dumbunny/vitess,fengshao0907/vitess,mahak/vitess,anusornc/vitess,vitessio/vitess,mapbased/vitess,mattharden/vitess,davygeek/vitess,alainjobart/vitess,mlc0202/vitess,enisoc/vitess,yaoshengzhe/vitess,skyportsystems/vitess,sougou/vitess,cloudbearings/vitess