How to find out the version of a package from its module

[chiraganand]

@fieker

I like the package manager and the declarative way, but I still need to be able to see and test the information. It has been part of Julia for a long time to e.g. check the Julia version to enable/ disable features. I can test for signatures being present, but I cannot test for a new algorithm being there unless the API changes.

Adding another use case: for development purposes. I (probably) found a bug in IndexedTables and I could not figure out which version am I running. PkgVersion.Version() eventually helped so that I know which branch of the code to look at.