Check ulimit in travis

.travis.yml

@@ -6,19 +6,16 @@ install:
   - sudo apt-get update || true
   # We do this conditionally because it saves us some downloading if the
   # version is the same.
-  - if [[ "$TRAVIS_PYTHON_VERSION" == "2.7" ]]; then
-      wget https://repo.continuum.io/miniconda/Miniconda2-latest-Linux-x86_64.sh -O miniconda.sh;
-    else
-      wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh;
-    fi
+  - wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh;
   - bash miniconda.sh -b -p $HOME/miniconda
   - export PATH="$HOME/miniconda/bin:$PATH"
   - hash -r
   - conda config --set always_yes yes --set changeps1 no
   - conda update -q conda || true
   # Useful for debugging any issues with conda
   - conda info -a
-
+  # Useful for debugging memory issues
+  - ulimit -a
   - free -m
   - conda env create -vv -n test-environment -f binder/environment.yml
   - source activate test-environment