Use https for codecov.io image
Use https for codecov.io image

--HG--
branch : salty_horse/use-https-for-codecovio-image-1519130663808

blueyed/coveragepy,hugovk/coveragepy,nedbat/coveragepy,nedbat/coveragepy,hugovk/coveragepy,hugovk/coveragepy,hugovk/coveragepy,blueyed/coveragepy,blueyed/coveragepy,blueyed/coveragepy,nedbat/coveragepy,nedbat/coveragepy,nedbat/coveragepy,hugovk/coveragepy,blueyed/coveragepy