Enable color output from integration tests in Docker containers (#16660)

Enable color output from integration tests in Docker containers:

* In run_tests.sh when output is attached to a terminal.
* In shippable/integration.sh using force mode (can be disabled).

Also fix blocks tests to work with or without color output

test/utils/shippable/integration.sh

@@ -13,6 +13,10 @@ http_image="${HTTP_IMAGE:-ansible/ansible:httptester}"
 keep_containers="${KEEP_CONTAINERS:-}"
 copy_source="${COPY_SOURCE:-}"
 
+# Force ansible color output by default.
+# To disable color force mode use FORCE_COLOR=0
+force_color="${FORCE_COLOR:-1}"
+
 if [ "${SHIPPABLE_BUILD_DIR:-}" ]; then
     host_shared_dir="/home/shippable/cache/build-${BUILD_NUMBER}"
     controller_shared_dir="/home/shippable/cache/build-${BUILD_NUMBER}"
@@ -69,6 +73,7 @@ fi
 
 httptester_id=$(docker run -d "${http_image}")
 container_id=$(docker run -d \
+    --env "ANSIBLE_FORCE_COLOR=${force_color}" \
     -v "/sys/fs/cgroup:/sys/fs/cgroup:ro" \
     -v "${host_shared_dir}:${test_shared_dir}" \
     --link="${httptester_id}:ansible.http.tests" \