Updating IGTF version:

- Find and download the latest igtf-policy-installation-bundle-<IGTF_VER>.tar.gz
  from https://dist.eugridpma.info/distribution/igtf/current/

- copy this igtf bundle tarball to the upstream area:
  igtf-policy-installation-bundle/<IGTF_VER>/igtf-policy-installation-bundle-<IGTF_VER>.tar.gz

- update {igtf,osg}-ca-certs/upstream/igtf.upstream.source in packaging with
  this new tarball + checksum

- inside new igtf bundle, get changes from CHANGES for the latest igtf release,
  add these changes to CHANGES here, in osg-certificates

- bump the igtf_version and osg_version in rpm/{igtf,osg}-ca-certs.spec,
  add changelog entries

- commit osg-certificates changes and tag v<OSG_VER>.igtf.<IGTF_VER>;
  push changes to opensciencegrid/osg-certificates (push master and new tag)
  
- update {igtf,osg}-ca-certs/upstream/osg-certificates.github.source in
  packaging; bump all occurances of OSG_VER and IGTF_VER, and update 'hash'
  to match the new tagged commit.

  NOTE: the 'name' parameter in osg-certificates.github.source matches the
  package name, {igtf,osg}-ca-certs, respectively.


Making OSG changes:

All OSG-specific stuff is done in "build-certificates-dir.sh" in the block
with the comment "OSG Specific stuff".

Currently the only thing here is to add letsencrypt certs, but in theory
other certs could be added or removed from here.


Updating Let's Encrypt certificates:

Let's Encrypt certificates are in the letsencrypt-certificates dir
as a Git submodule from
https://github.com/opensciencegrid/letsencrypt-certificates

To update the submodule, make sure it's checked out in your local clone:

  $ git submodule update --init letsencrypt-certificates

Fetch and switch to the desired tag:

  $ cd letsencrypt-certificates
  $ git fetch --tags
  $ git switch --detach <TAG>

Then add and commit the change:

  $ cd ..
  $ git add letsencrypt-certificates
  $ git commit -m "Update letsencrypt-certificates submodule to <TAG>"