Support prepend argument in TBLogger constructor

[ancapdev]

I'm working on a project where I run multiple threads producing tensorboard events for the same run (sharing a log directory), each thread producing events for different tags. The time() based file naming mechanism isn't guaranteed to avoid, and in fact leads to, collisions under this use case. To resolve the problem I've added support for the existing create_eventfile() prepend argument to TBLogger().

Appreciate your reviewing and considering this small change. Thanks

[PhilipVinc]

Hi and thanks for your contribution.

Maybe a better name would be prefix, which is more consistent with what is used in a few cases in the sdtlib.
Can you change it in the TBLogger constructor?

Also, could you add a line to the docstring explaining what it does (mentioning that it's the prefix of the files and not of the folder directory).
If you have the time, also adding a test that checks that it indeed works would be great.

[PhilipVinc]

Also, For the moment I'm trying to support older (Julia>=1.3) versions so you cannot use the short kwargs syntax

[PhilipVinc]

Otherwise this seems fine.
If you address the comments above i'll merge and quickly tag a new release.

[ancapdev]

Sure, sounds good. Do you want it named prefix in create_eventfile() as well? I was just trying to be consistent with that.

[PhilipVinc]

yes if you can rename it it would be great