Update readme.md to include php fall back
Update readme.md to include php fall back

Update the README.md to include the php only command to install
composer incase curl is not available

composer/composer,nevvermind/composer,fabiang/composer,JBleijenberg/composer,Seldaek/composer,nicolas-grekas/composer,alcohol/composer,MoT3rror/composer,DiceHoldingsInc/composer,curry684/composer,yaman-jain/composer,Teino1978-Corp/Teino1978-Corp-composer,stefangr/composer,balbuf/composer,pierredup/composer,Danack/composer,till/composer,johnstevenson/composer,floverdevel/composer,localheinz/composer,bd808/composer,dzuelke/composer,davidolrik/composer,staabm/composer,slbmeh/composer,naderman/composer,SpacePossum/composer,andrerom/composer,remicollet/composer,vdm-io/composer,javihgil/composer,jreinke/composer,Soullivaneuh/composer,milleruk/composer,fabpot/composer,phansys/composer,stof/composer,hirak/composer,erasys/composer,gencer/composer