Bump Pandas version

Required by numpy version bump

Author: effigies

Dockerfile

@@ -111,7 +111,7 @@ RUN conda install -y mkl=2018.0.3 mkl-service;  sync &&\
                      scipy=1.1.0 \
                      scikit-learn=0.19.1 \
                      matplotlib=2.2.0 \
-                     pandas=0.19.2 \
+                     pandas=0.23.0 \
                      libxml2=2.9.4 \
                      libxslt=1.1.29\
                      traits=4.6.0; sync &&  \