Prepends the http:// scheme if necessary to a url. Fails if a scheme
    other than http is used

def fix_scheme(url):
    '''Prepends the http:// scheme if necessary to a url. Fails if a scheme
    other than http is used'''
    splitted = url.split('://')
    if len(splitted) == 2:
        if splitted[0] in ('http', 'https'):
            return url
        else:
            raise exc.WileECoyoteException(
                'Bad scheme! Got: {}, expected http or https'.format(
                    splitted[0]))
    elif len(splitted) == 1:
        return 'http://' + url
    else:
        raise exc.ZachMorrisException('Too many schemes!')