list installed package versions for diagnostics

if the code doesn't work for the user, s/he can check travis for which versions did work

.travis.yml

@@ -34,6 +34,7 @@ before_script:
 # download imagenet validation now to avoid out-of-memory errors in script
 - sudo -H pip install awscli --upgrade --ignore-installed six  # aws dependency issue: https://github.com/aws/aws-cli/issues/1522#issuecomment-159007931
 - aws --no-sign-request --region=us-east-1 s3 cp s3://brain-score-models/imagenet2012-val.hdf5 ./imagenet2012.hdf5
+- conda list # list installed package versions
 script:
 - if [ "$TRAVIS_PULL_REQUEST" = "false"];  then CUDA_VISIBLE_DEVICES= MT_MULTITHREAD=0 MT_IMAGENET_PATH=./imagenet2012.hdf5 pytest --ignore=tf-models --skip-memory-intense; fi
 - if [ "$TRAVIS_PULL_REQUEST" = "true" ];  then CUDA_VISIBLE_DEVICES= MT_MULTITHREAD=0 MT_IMAGENET_PATH=./imagenet2012.hdf5 pytest --ignore=tf-models --skip-memory-intense --skip-private; fi