now that we have working Travis support for testing proto2 and proto3, here is a first cleanup of adding the proto2 declaration desired by proto3 (and ignored by proto2).
in doing this one unit test needn't to be deactivated, you see it below -- it is file permission corner case in the temp directory and maybe just maybe something changed with R. not sure, but also not super important.
adding 'proto2' declaration; temp. deactivating addressbook test
will look into why addressbook test failed
commitinf changes as test for v2 + v3 Travis setup
previously tested against custom Docker images with v2 and v3
runit.addressbook runs all but one of its tests
Comments, anyone? If not I plan to merge later this evening.