update cython version

Author: mfeurer

.travis.yml

@@ -17,8 +17,8 @@ env:
   matrix:
   - DISTRIB="conda" PYTHON_VERSION="2.7" NUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.21" SKLEARN_VERSION="0.18"
   - DISTRIB="conda" PYTHON_VERSION="3.4" NUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.23.4" SKLEARN_VERSION="0.18"
-  - DISTRIB="conda" PYTHON_VERSION="3.5" CNUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.23.4" SKLEARN_VERSION="0.18"
-  - DISTRIB="conda" PYTHON_VERSION="3.6" COVERAGE="true" NUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.23.4" SKLEARN_VERSION="0.18"
+  - DISTRIB="conda" PYTHON_VERSION="3.5" NUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.23.4" SKLEARN_VERSION="0.18"
+  - DISTRIB="conda" PYTHON_VERSION="3.6" COVERAGE="true" NUMPY_VERSION="1.11" SCIPY_VERSION="0.17.0" CYTHON_VERSION="0.25.2" SKLEARN_VERSION="0.18"
 
 install: source ci_scripts/install.sh
 script: bash ci_scripts/test.sh