Reorder steps in Travis to avoid rebuilding on `mach test-unit`
Reorder steps in Travis to avoid rebuilding on `mach test-unit`

CJ8664/servo,emilio/servo,canaltinova/servo,thiagopnts/servo,nnethercote/servo,nnethercote/servo,mattnenterprise/servo,notriddle/servo,KiChjang/servo,dsandeephegde/servo,saneyuki/servo,saneyuki/servo,cbrewster/servo,mbrubeck/servo,notriddle/servo,sadmansk/servo,saneyuki/servo,avadacatavra/servo,thiagopnts/servo,upsuper/servo,saneyuki/servo,pyfisch/servo,DominoTree/servo,fiji-flo/servo,nnethercote/servo,anthgur/servo,rnestler/servo,sadmansk/servo,splav/servo,larsbergstrom/servo,canaltinova/servo,notriddle/servo,pyfisch/servo,dsandeephegde/servo,nnethercote/servo,splav/servo,ConnorGBrewster/servo,mbrubeck/servo,KiChjang/servo,emilio/servo,mbrubeck/servo,paulrouget/servo,dsandeephegde/servo,mbrubeck/servo,peterjoel/servo,eddyb/servo,cbrewster/servo,paulrouget/servo,ConnorGBrewster/servo,thiagopnts/servo,avadacatavra/servo,dati91/servo,thiagopnts/servo,dsandeephegde/servo,canaltinova/servo,nnethercote/servo,anthgur/servo,pyfisch/servo,dsandeephegde/servo,canaltinova/servo,dati91/servo,thiagopnts/servo,upsuper/servo,pyfisch/servo,splav/servo,jimberlage/servo,peterjoel/servo,szeged/servo,jimberlage/servo,rnestler/servo,notriddle/servo,mattnenterprise/servo,upsuper/servo,paulrouget/servo,paulrouget/servo,saneyuki/servo,saneyuki/servo,DominoTree/servo,KiChjang/servo,KiChjang/servo,upsuper/servo,saneyuki/servo,sadmansk/servo,szeged/servo,ConnorGBrewster/servo,anthgur/servo,larsbergstrom/servo,emilio/servo,DominoTree/servo,KiChjang/servo,rnestler/servo,cbrewster/servo,szeged/servo,splav/servo,eddyb/servo,pyfisch/servo,jimberlage/servo,rnestler/servo,fiji-flo/servo,cbrewster/servo,peterjoel/servo,rnestler/servo,DominoTree/servo,paulrouget/servo,larsbergstrom/servo,ConnorGBrewster/servo,jimberlage/servo,SimonSapin/servo,notriddle/servo,avadacatavra/servo,SimonSapin/servo,szeged/servo,KiChjang/servo,SimonSapin/servo,pyfisch/servo,paulrouget/servo,emilio/servo,splav/servo,SimonSapin/servo,szeged/servo,dati91/servo,mattnenterprise/servo,paulrouget/servo,canaltinova/servo,jimberlage/servo,DominoTree/servo,SimonSapin/servo,nnethercote/servo,mbrubeck/servo,nnethercote/servo,mbrubeck/servo,pyfisch/servo,eddyb/servo,SimonSapin/servo,canaltinova/servo,szeged/servo,notriddle/servo,larsbergstrom/servo,fiji-flo/servo,splav/servo,saneyuki/servo,avadacatavra/servo,ConnorGBrewster/servo,SimonSapin/servo,DominoTree/servo,DominoTree/servo,DominoTree/servo,mbrubeck/servo,peterjoel/servo,anthgur/servo,upsuper/servo,CJ8664/servo,larsbergstrom/servo,larsbergstrom/servo,sadmansk/servo,DominoTree/servo,cbrewster/servo,fiji-flo/servo,ConnorGBrewster/servo,mattnenterprise/servo,mattnenterprise/servo,splav/servo,SimonSapin/servo,peterjoel/servo,KiChjang/servo,avadacatavra/servo,peterjoel/servo,thiagopnts/servo,dati91/servo,mattnenterprise/servo,eddyb/servo,larsbergstrom/servo,DominoTree/servo,eddyb/servo,notriddle/servo,pyfisch/servo,thiagopnts/servo,CJ8664/servo,emilio/servo,CJ8664/servo,cbrewster/servo,anthgur/servo,paulrouget/servo,avadacatavra/servo,anthgur/servo,sadmansk/servo,cbrewster/servo,emilio/servo,paulrouget/servo,sadmansk/servo,saneyuki/servo,upsuper/servo,ConnorGBrewster/servo,rnestler/servo,KiChjang/servo,avadacatavra/servo,ConnorGBrewster/servo,upsuper/servo,dsandeephegde/servo,peterjoel/servo,notriddle/servo,emilio/servo,splav/servo,sadmansk/servo,thiagopnts/servo,dati91/servo,notriddle/servo,dsandeephegde/servo,CJ8664/servo,canaltinova/servo,nnethercote/servo,pyfisch/servo,cbrewster/servo,splav/servo,CJ8664/servo,avadacatavra/servo,anthgur/servo,jimberlage/servo,dati91/servo,mattnenterprise/servo,larsbergstrom/servo,szeged/servo,dsandeephegde/servo,mbrubeck/servo,szeged/servo,eddyb/servo,rnestler/servo,paulrouget/servo,CJ8664/servo,szeged/servo,peterjoel/servo,anthgur/servo,peterjoel/servo,larsbergstrom/servo,saneyuki/servo,fiji-flo/servo,eddyb/servo,pyfisch/servo,CJ8664/servo,upsuper/servo,jimberlage/servo,nnethercote/servo,eddyb/servo,dati91/servo,fiji-flo/servo,jimberlage/servo,mattnenterprise/servo,canaltinova/servo,fiji-flo/servo,sadmansk/servo,KiChjang/servo,dati91/servo,rnestler/servo,szeged/servo,emilio/servo,KiChjang/servo,emilio/servo,emilio/servo,jimberlage/servo,fiji-flo/servo,nnethercote/servo,peterjoel/servo,notriddle/servo,splav/servo,larsbergstrom/servo