add coverage from coveralls to README for wip0.3
add coverage from coveralls to README for wip0.3

GLMeece/faker,johnraz/faker,HAYASAKA-Ryosuke/faker,xfxf/faker-1,beetleman/faker,ericchaves/faker,thedrow/faker,xfxf/faker-python,joke2k/faker,yiliaofan/faker,trtd/faker,MaryanMorel/faker,danhuss/faker,meganlkm/faker,ShaguptaS/faker,joke2k/faker,venmo/faker,jaredculp/faker