[stable-2.8] Handle get-pip.py breaking change on Python 2.7.

(cherry picked from commit 484e4af4d0)

Co-authored-by: Matt Clay <matt@mystile.com>

changelogs/fragments/ansible-test-pip-bootstrap.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ansible-test - The ``--remote`` option has been updated for Python 2.7 to work around breaking changes in the newly released ``get-pip.py`` bootstrapper.

test/runner/setup/remote.sh

@@ -10,7 +10,15 @@ cd ~/
 
 install_pip () {
     if ! "${python_interpreter}" -m pip.__main__ --version --disable-pip-version-check 2>/dev/null; then
-        curl --silent --show-error https://bootstrap.pypa.io/get-pip.py -o /tmp/get-pip.py
+        case "${python_version}" in
+            "2.7")
+                pip_bootstrap_url="https://bootstrap.pypa.io/${python_version}/get-pip.py"
+                ;;
+            *)
+                pip_bootstrap_url="https://bootstrap.pypa.io/get-pip.py"
+                ;;
+        esac
+        curl --silent --show-error "${pip_bootstrap_url}" -o /tmp/get-pip.py
         "${python_interpreter}" /tmp/get-pip.py --disable-pip-version-check --quiet
         rm /tmp/get-pip.py
     fi