Set codecov after_n_builds to 10 as a test
Set codecov after_n_builds to 10 as a test

This should fix the issue that codecov reported a coverage percentage
which didn't take all builds into account (due to cancellation)

There are currently 29 travis builds so 10 should be a safe number

jnns/wagtail,nealtodd/wagtail,gasman/wagtail,gasman/wagtail,jnns/wagtail,rsalmaso/wagtail,torchbox/wagtail,zerolab/wagtail,kaedroho/wagtail,thenewguy/wagtail,kaedroho/wagtail,wagtail/wagtail,FlipperPA/wagtail,mixxorz/wagtail,FlipperPA/wagtail,rsalmaso/wagtail,rsalmaso/wagtail,iansprice/wagtail,takeflight/wagtail,FlipperPA/wagtail,FlipperPA/wagtail,nimasmi/wagtail,timorieber/wagtail,mikedingjan/wagtail,timorieber/wagtail,zerolab/wagtail,torchbox/wagtail,nealtodd/wagtail,jnns/wagtail,mixxorz/wagtail,zerolab/wagtail,thenewguy/wagtail,nimasmi/wagtail,timorieber/wagtail,mixxorz/wagtail,gasman/wagtail,takeflight/wagtail,kaedroho/wagtail,wagtail/wagtail,iansprice/wagtail,torchbox/wagtail,rsalmaso/wagtail,nealtodd/wagtail,thenewguy/wagtail,mikedingjan/wagtail,mixxorz/wagtail,rsalmaso/wagtail,timorieber/wagtail,mikedingjan/wagtail,mikedingjan/wagtail,takeflight/wagtail,nimasmi/wagtail,wagtail/wagtail,zerolab/wagtail,nimasmi/wagtail,takeflight/wagtail,kaedroho/wagtail,zerolab/wagtail,gasman/wagtail,iansprice/wagtail,nealtodd/wagtail,wagtail/wagtail,gasman/wagtail,wagtail/wagtail,mixxorz/wagtail,thenewguy/wagtail,thenewguy/wagtail,iansprice/wagtail,kaedroho/wagtail,jnns/wagtail,torchbox/wagtail