gitlab/travis: Rework how and when we use virtualenv in order to use python3

As things stand today, we have tools that CI requires where "python"
must be "python2".  We need to use a virtualenv and pip in order to
ensure that our pytest tests can be run.  Rework things slightly so
that:
- On Travis-CI, we install python-pyelftools for the platforms that
  require pyelftools to be installed.
- On GitLab-CI, we move to a newer base image that includes python3-pip
  and continue to use a virtualenv per job that needs it, for the
  correct set of packages.

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Simon Glass <sjg@chromium.org> [on sandbox]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5a34321..9b295ac 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,7 +2,7 @@
 
 # Grab our configured image.  The source for this is found at:
 # https://gitlab.denx.de/u-boot/gitlab-ci-runner
-image: trini/u-boot-gitlab-ci-runner:bionic-20190912.1-03Oct2019
+image: trini/u-boot-gitlab-ci-runner:bionic-20191010-20Oct2019
 
 # We run some tests in different order, to catch some failures quicker.
 stages:
@@ -18,11 +18,6 @@
     - git clone --depth=1 git://github.com/swarren/uboot-test-hooks.git /tmp/uboot-test-hooks
     - ln -s travis-ci /tmp/uboot-test-hooks/bin/`hostname`
     - ln -s travis-ci /tmp/uboot-test-hooks/py/`hostname`
-    - virtualenv /tmp/venv
-    - . /tmp/venv/bin/activate
-    - pip install pytest
-    - pip install python-subunit
-    - pip install coverage
     - grub-mkimage --prefix="" -o ~/grub_x86.efi -O i386-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
     - grub-mkimage --prefix="" -o ~/grub_x64.efi -O x86_64-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
     - mkdir ~/grub2-arm
@@ -47,6 +42,9 @@
     # never prevent any test from running. That way, we can always pass
     # "-k something" even when $TEST_PY_TEST_SPEC doesnt need a custom
     # value.
+    - virtualenv -p /usr/bin/python3 /tmp/venv
+    - . /tmp/venv/bin/activate
+    - pip install -r test/py/requirements.txt
     - export UBOOT_TRAVIS_BUILD_DIR=/tmp/.bm-work/${TEST_PY_BD};
       export PATH=/opt/qemu/bin:/tmp/uboot-test-hooks/bin:${PATH};
       export PYTHONPATH=/tmp/uboot-test-hooks/py/travis-ci;