ci: remove ubuntu 18.04

* Ubuntu 18.04 will no longer be supported.
* INSTALL.md includes a list of operating systemes in the CI.

Signed-off-by: Juergen Repp <juergen_repp@web.de>

.github/workflows/main.yml

@@ -7,7 +7,7 @@ jobs:
     if: "!contains(github.ref, 'coverity_scan')"
     strategy:
       matrix:
-        docker_image: [ubuntu-18.04, ubuntu-20.04, fedora-32, opensuse-leap, ubuntu-22.04, alpine-3.15]
+        docker_image: [ubuntu-20.04, fedora-32, opensuse-leap, ubuntu-22.04, alpine-3.15]
         compiler: [gcc, clang]
     steps:
       - name: Check out repository
@@ -117,7 +117,7 @@ jobs:
           tpm2-software/ci/runCI@main
         with:
           CC: gcc
-          DOCKER_IMAGE: ubuntu-18.04
+          DOCKER_IMAGE: ubuntu-20.04
           ENABLE_COVERAGE: true
           PROJECT_NAME: ${{ github.event.repository.name }}
       - name: failure
@@ -159,7 +159,7 @@ jobs:
           REPO_BRANCH: ${{ github.ref }}
           REPO_NAME: ${{ github.repository }}
           ENABLE_COVERITY: true
-          DOCKER_IMAGE: ubuntu-18.04
+          DOCKER_IMAGE: ubuntu-20.04
           CC: gcc
           COVERITY_SCAN_TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}
           COVERITY_SUBMISSION_EMAIL: tadeusz.struk@intel.com

INSTALL.md

@@ -178,6 +178,12 @@ $ sudo udevadm control --reload-rules && sudo udevadm trigger
 If this doesn't work on your distro please consult your distro's
 documentation for UDEVADM(8).
 
+Users who should have access to the TPM and the FAPI keystore should be
+included in the tss group.
+​```
+ sudo usermod -aG tss <username>
+ ```
+
 ## ldconfig
 
 It may be necessary to run ldconfig (as root) to update the run-time
@@ -248,4 +254,13 @@ for cortex-m4:
         CFLAGS='-mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 -mthumb' \
         LDFLAGS='--specs=nosys.specs'
 make
-```
+```
+
+## Test operating systems in the CI
+
+* ubuntu-20.04
+* fedora-32
+* opensuse-leap
+* ubuntu-22.04
+* alpine-3.15
+* FreeBSD