Update Ubuntu & Python Versions in CI

Author: sdimitro

.github/scripts/install-libkdumpfile.sh

@@ -8,7 +8,7 @@
 #
 sudo apt update
 sudo apt install autoconf automake liblzo2-dev libsnappy1v5 libtool pkg-config zlib1g-dev
-sudo apt install python3.6-dev python3.7-dev python3.8-dev
+sudo apt install python3.8-dev
 
 git clone https://github.com/ptesarik/libkdumpfile.git
 

.github/workflows/main.yml

@@ -9,10 +9,10 @@ jobs:
   # Verify the build and installation of SDB.
   #
   install:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.8]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
@@ -31,12 +31,12 @@ jobs:
   # the "drgn" from source (there's no package currently available).
   #
   pylint:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
         with:
-          python-version: '3.6'
+          python-version: '3.8'
       - run: ./.github/scripts/install-drgn.sh
       - run: python3 -m pip install pylint pytest
       - run: pylint -d duplicate-code -d invalid-name sdb
@@ -52,10 +52,10 @@ jobs:
   # can open kdump-compressed crash dumps for the integration tests.
   #
   pytest:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.8]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
@@ -73,12 +73,12 @@ jobs:
   # Verify "yapf" runs successfully.
   #
   yapf:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
         with:
-          python-version: '3.6'
+          python-version: '3.8'
       - run: python3 -m pip install yapf
       - run: yapf --diff --style google --recursive sdb
       - run: yapf --diff --style google --recursive tests
@@ -98,12 +98,12 @@ jobs:
   #     pytest doesn't provide stubs on typeshed.
   #
   mypy:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
         with:
-          python-version: '3.6'
+          python-version: '3.8'
       - run: ./.github/scripts/install-drgn.sh
       - run: python3 -m pip install mypy==0.730
       - run: python3 -m mypy --strict --show-error-codes -p sdb
@@ -112,7 +112,7 @@ jobs:
   # Verify that "shfmt" ran successfully against our shell scripts.
   #
   shfmt:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: delphix/actions/shfmt@master