Dependency check

[scarlehoff]

c.f. #181 (comment)

Since pineko is going to be lacking a maintainer (but at the same time it is close to be feature complete by now) it would be nice to periodically check that eko and pineappl have not diverged much so that it can be kept up to date with minimal effort.

[felixhekhorn]

#215 is a big step towards this - it has no time trigger however. Should we keep the issue just for that or close?

[Radonirinaunimi]

Indeed! This can be considered done.