Add warning for python 2.7 on release/v3 (#674)

* add warning

* npm run format

* remove ubuntu-18.04

.github/workflows/test-pypy.yml

@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-18.04, ubuntu-latest]
+        os: [macos-latest, windows-latest, ubuntu-latest]
         pypy:
         - 'pypy-2.7'
         - 'pypy-3.7'

.github/workflows/test-python.yml

@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-18.04, ubuntu-20.04]
+        os: [macos-latest, windows-latest, ubuntu-20.04]
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -38,7 +38,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-18.04, ubuntu-20.04]
+        os: [macos-latest, windows-latest, ubuntu-20.04]
         python: [3.5.4, 3.6.7, 3.7.5, 3.8.1]
     steps:
     - name: Checkout
@@ -68,7 +68,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-18.04, ubuntu-20.04]
+        os: [macos-latest, windows-latest, ubuntu-20.04]
     steps:
     - name: Checkout
       uses: actions/checkout@v2

.github/workflows/workflow.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.operating-system }}
     strategy:
       matrix:
-        operating-system: [ubuntu-latest, windows-latest]
+        operating-system: [ubuntu-20.04, windows-latest]
     steps:
     - name: Checkout
       uses: actions/checkout@v2

src/setup-python.ts

@@ -34,6 +34,11 @@ async function run() {
           `Successfully setup PyPy ${installed.resolvedPyPyVersion} with Python (${installed.resolvedPythonVersion})`
         );
       } else {
+        if (version.trim().startsWith('2')) {
+          core.warning(
+            'The support for python 2.7 will be removed on June 19. Related issue: https://github.com/actions/setup-python/issues/672'
+          );
+        }
         const installed = await finder.useCpythonVersion(version, arch);
         pythonVersion = installed.version;
         core.info(`Successfully setup ${installed.impl} (${pythonVersion})`);