Dependency updates

[tgalery]

Looking at the contribution graph, many people are using this repo and essentially updating its dependencies. Is this still maintained ? Are contributions welcome ?

[javer]

@tgalery Yes, feel free to open PR with the suggested changes, including dependency updates.

Don't forget that a library shouldn't require a new version of the 3rd-party dependency unless it actually depends on the new features of it (i.e. doesn't work with the previous versions). So, let's say, if you want to add support for aws_common v0.7.x and this is the only change (no actual code changes) - you should use the version constraint like >=0.6.0 instead of ^0.7.0, otherwise you will limit application capabilities to use specific (and also old) versions of these 3rd-party dependencies.