using updated toolchain

.travis.yml

@@ -8,6 +8,10 @@ dist: trusty
 install:
   # We do this conditionally because it saves us some downloading if the
   # version is the same.
+  - sudo add-apt-repository ppa:ubuntu-toolchain-r/test
+  - sudo apt-get update
+  - sudo apt-get upgrade
+  - sudo apt-get dist-upgrade
   - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
   - sudo apt-get -qq update
   - sudo apt-get -qq install g++-5
@@ -36,7 +40,6 @@ install:
   - conda install pandas
   - conda install scikit-learn
   - conda install cython
-  - conda install libgcc
   - conda install -c conda-forge arrow
   - pip install simpleutils
   - pip install coveralls