Test newer version of cython

Author: isuruf

appveyor.yml

@@ -62,7 +62,7 @@ install:
 
 - set PATH=C:\Python%PYTHON_VERSION%;C:\Python%PYTHON_VERSION%\Scripts;%PATH%
 - pip install nose pytest sympy
-- pip install --install-option="--no-cython-compile" cython==0.23
+- pip install --install-option="--no-cython-compile" cython
 
 - set /p commit=<symengine_version.txt
 - cd symengine-cpp

bin/install_travis.sh

@@ -12,11 +12,7 @@ if [[ "${WITH_SAGE}" != "yes" ]]; then
     conda config --set always_yes yes --set changeps1 no;
     conda update -q conda;
     conda info -a;
-    CYTHON_VERSION=0.23
-    if [[ "${PYTHON_VERSION}" == "2.6" ]] || [[ "${PYTHON_VERSION}" == "3.3" ]]; then
-        CYTHON_VERSION=0.22
-    fi
-    CONDA_PKGS="pip cython=${CYTHON_VERSION} sympy nose pytest"
+    CONDA_PKGS="pip cython sympy nose pytest"
     if [[ "${WITH_NUMPY}" == "yes" ]]; then
         CONDA_PKGS="${CONDA_PKGS} numpy";
     fi