Allow creating multiple connections and select which one to use

[swantzter]

fixes #24

[CLAassistant]

All committers have signed the CLA.

[swantzter]

I tried to keep this non-breaking which in some cases resulted in an added positional argument that takes an options struct, but relies on existing options structs if they exist. But I'm open to other alternatives, even going to options arguments across the board and thus breaking the API

[javaducky]

Please rebase as this has merge conflicts given merge of #26 .

[swantzter]

@javaducky sorry for the delay, I was enjoying a vacation away from a proper computer :) think it should be sorted now

[javaducky]

@swantzter thank you! Looks like there are some linter issues related to missing documentation for the *.GetConn functions.

[swantzter]

@javaducky yeah I was looking at them, but I can't see how what I've done differs from how the rest of the library code does it, do you have any pointers for how to align it?

[javaducky]

With method documentation, the comment should begin with the actual name of the method/function itself.

[javaducky]

LGTM! Thank you for getting those updates!