Improve jinja2 test coverage. (#20533)

* Run `template` test on latest jinja2 version.
* Update jinja2 install for groupby_filter.
* Clean test output dir for each test.

test/integration/targets/template_jinja2_latest/aliases

@@ -0,0 +1 @@
+../template/aliases

test/integration/targets/template_jinja2_latest/main.yml

@@ -0,0 +1,4 @@
+- hosts: testhost
+  gather_facts: True
+  roles:
+    - { role: template }

test/integration/targets/template_jinja2_latest/roles/template

@@ -0,0 +1 @@
+../../template

test/integration/targets/template_jinja2_latest/runme.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+# We don't set -u here, due to pypa/virtualenv#150
+set -ex
+
+MYTMPDIR=$(mktemp -d 2>/dev/null || mktemp -d -t 'mytmpdir')
+
+trap 'rm -rf "${MYTMPDIR}"' EXIT
+
+# This is needed for the ubuntu1604py3 tests
+# Ubuntu patches virtualenv to make the default python2
+# but for the python3 tests we need virtualenv to use python3
+PYTHON=$("python${ANSIBLE_TEST_PYTHON_VERSION:-}" -c "import sys; print(sys.executable)")
+
+virtualenv --system-site-packages --python "${PYTHON}" "${MYTMPDIR}/jinja2"
+
+source "${MYTMPDIR}/jinja2/bin/activate"
+
+pip install -U jinja2
+
+ansible-playbook -i ../../inventory main.yml -e @../../integration_config.yml -v "$@"