adding travis images to README.md
adding travis images to README.md

tomkralidis/pywps,ldesousa/PyWPS,doclements/pywps-4,ricardogsilva/PyWPS,bird-house/PyWPS,jachym/PyWPS,SiggyF/pywps-4,geopython/pywps,jonas-eberle/pywps