added build image to README.md
added build image to README.md

stewbawka/catarse_wepay,centaurustech/catarse_paypal_express,Betahackers/catarse_offline_payment,MHBA/catarse_paypal_express,tbly/catarse_paypal_adaptive,stewbawka/catarse_wepay,devton/catarse_paypal_express,joshblour/catarse_paypal_adaptive,Betahackers/catarse_offline_payment,cesvald/catarse_paypal_express,cesvald/catarse_paypal_express,centaurustech/catarse_paypal_express,Betahackers/catarse_offline_payment,cesvald/catarse_paypal_express,stewbawka/catarse_wepay,tbly/catarse_paypal_adaptive,tbly/catarse_paypal_adaptive,joshblour/catarse_paypal_adaptive,centaurustech/catarse_paypal_express,devton/catarse_paypal_express,joshblour/catarse_paypal_adaptive,MHBA/catarse_paypal_express