Use same style of release names as official exporters

[Perflyst]

Proposed changes

The official prometheus exporters use all the same naming scheme. You used a - instead of a . for whatever reason.
To make it easier to download exporters, in standardized ways, it would be good if everyone follows this schema.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING guide
• I have proven my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have ensured the README is up to date
• I have rebased my branch onto master
• I will ensure my PR is targeting the master branch and pulling from my branch on my own fork

[LorcanMcVeigh]

Hey @Perflyst

Thanks for the PR. This looks good to me and makes sense

we typically get 2 people to approve before merging, so just let the other guys take a look at it first before merging.

[rosaLux161]

Good for some, bad for others. If the script aborts when updating the version number because the naming structure has changed. :D