Rip out Python 2.

.github/workflows/ci.yml

@@ -38,14 +38,11 @@ jobs:
           - windows-latest
           - ubuntu-latest
         python-version:
-          - 2.7
           - 3.7
           - 3.8
           - 3.9
         include:
           # On macOS don't bother with 3.7-3.8, just to get faster builds.
-          - os: macos-10.15
-            python-version: 2.7
           - os: macos-latest
             python-version: 3.9
 
@@ -108,25 +105,6 @@ jobs:
       # Action for this, as of Jan 2021 it does not support Python coverage
       # files - only lcov files.  Therefore, we use coveralls-python, the
       # coveralls.io-supplied Python reporter, for this.
-      #
-      # It is coveralls-python 1.x that has maintained compatibility
-      # with Python 2, while coveralls-python 3.x is compatible with
-      # Python 3.  Sadly we can't use them both in the same workflow.
-      #
-      # The two versions of coveralls-python are somewhat mutually
-      # incompatible.  Mixing these two different versions when
-      # reporting coverage to coveralls.io will lead to grief, since
-      # they get job IDs in different fashion.  If we use both
-      # versions of coveralls in the same workflow, the finalizing
-      # step will be able to mark only part of the jobs as done, and
-      # the other part will be left hanging, never marked as done: it
-      # does not matter if we make an API call or `coveralls --finish`
-      # to indicate that CI has finished running.
-      #
-      # So we try to use the newer coveralls-python that is available
-      # via Python 3 (which is present in GitHub Actions tool cache,
-      # even when we're running Python 2.7 tests) throughout this
-      # workflow.
       - name: "Report Coverage to Coveralls"
         run: |
           pip3 install --upgrade coveralls==3.0.1
@@ -179,13 +157,10 @@ jobs:
           - windows-latest
           - ubuntu-latest
         python-version:
-          - 2.7
           - 3.7
           - 3.9
         include:
           # On macOS don't bother with 3.7, just to get faster builds.
-          - os: macos-10.15
-            python-version: 2.7
           - os: macos-latest
             python-version: 3.9
 
@@ -242,12 +217,7 @@ jobs:
       - name: Display tool versions
         run: python misc/build_helpers/show-tool-versions.py
 
-      - name: Run "Python 2 integration tests"
-        if: ${{ matrix.python-version == '2.7' }}
-        run: tox -e integration
-
       - name: Run "Python 3 integration tests"
-        if: ${{ matrix.python-version != '2.7' }}
         run: tox -e integration3
 
       - name: Upload eliot.log in case of failure
@@ -267,7 +237,7 @@ jobs:
           - windows-latest
           - ubuntu-latest
         python-version:
-          - 2.7
+          - 3.9
 
     steps: