[gitlab-ci] Use a conda environment to run the tests

Currently the environment is "pre-created" on the runner
machine.

.gitlab-ci.yml

@@ -4,6 +4,8 @@ stages:
 variables:
   PREFIX: /opt/beat.env.web/usr
   TEST_PREFIX_PATH_FILE: 'test_prefix_$CI_JOB_ID.txt'
+  CONDA_ENV_NAME: beat_test_env
+  CONDA_PREFIX: /local/opt/conda
 
 build:
   stage: build
@@ -15,6 +17,9 @@ build:
   - git clean -ffdx
   - export BEAT_TEST_PREFIX=`mktemp -d --tmpdir=/var/tmp beat_test_prefix.XXXXXXXXX`
   - echo $BEAT_TEST_PREFIX > $TEST_PREFIX_PATH_FILE
+  - export PATH="$CONDA_PREFIX/bin:$PATH"
+  - source activate $CONDA_ENV_NAME
+  - conda info --envs
   script:
   - ${PREFIX}/bin/python bootstrap-buildout.py
   - ./bin/buildout