tryout design of filter support
simple counter creation
handle travis complaint
travis weirdness
on 500 write error string
travis tryout
travis tryout (2)
travis tryout(3)
restore old travis file
travis -> drone
implemented webservice and route level filter chains

see restful-filters.go for an example
fix Filters() in WebService
add global filters
docs about filters and errors
add tests for filters
add basic authentication example filter