use conda version for install to try to fix enum34 dependency issue

.travis.yml

@@ -24,7 +24,11 @@ matrix:
 notifications:
   email: false
 before_install:
-- wget https://repo.continuum.io/miniconda/Miniconda-latest-Linux-x86_64.sh -O miniconda.sh
+# Using the major Python version in the conda installer fixes this error:
+#UnsatisfiableError: The following specifications were found to be in conflict:
+#  - enum34 -> python 2.6*|2.7*|3.3*
+#  - python 3.4*
+- wget https://repo.continuum.io/miniconda/Miniconda${TRAVIS_PYTHON_VERSION:0:1}-latest-Linux-x86_64.sh -O miniconda.sh
 - chmod +x miniconda.sh
 - INSTALL_DIR=${HOME}
 - ./miniconda.sh -b -p ${INSTALL_DIR}/miniconda