Configure encoding to be utf-8 (#160)

Author: yangaws

docker/1.12.0/Dockerfile.cpu

@@ -62,7 +62,7 @@ RUN if [ $py_version -eq 3 ]; then PYTHON_VERSION=python3.6; else PYTHON_VERSION
         ln -s -f /usr/bin/$PYTHON_VERSION /usr/bin/python && \
     rm -rf /var/lib/apt/lists/*
 
-ENV PYTHONDONTWRITEBYTECODE=1 PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1 PYTHONUNBUFFERED=1 PYTHONIOENCODING=UTF-8 LANG=C.UTF-8 LC_ALL=C.UTF-8
 
 RUN curl -fSsL -O https://bootstrap.pypa.io/get-pip.py && \
     python get-pip.py --disable-pip-version-check --no-cache-dir "pip==18.1" && \

docker/1.12.0/Dockerfile.gpu

@@ -96,7 +96,7 @@ RUN mkdir -p /root/.ssh/ && \
 
 ###########################################################################
 # Python won’t try to write .pyc or .pyo files on the import of source modules
-ENV PYTHONDONTWRITEBYTECODE=1 PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1 PYTHONUNBUFFERED=1 PYTHONIOENCODING=UTF-8 LANG=C.UTF-8 LC_ALL=C.UTF-8
 
 RUN curl -fSsL -O https://bootstrap.pypa.io/get-pip.py && \
     python get-pip.py --disable-pip-version-check --no-cache-dir "pip==18.1" && \