Specify the horovod version in docker test file

Author: BichengYing

.travis.yml

@@ -28,8 +28,8 @@ addons:
 
 before_install:
     - ./scripts/install_mpi.sh $MPI
-    - pip$PY install numpy==1.18.1
     - pip$PY install torch==1.4.0
+    - pip$PY install numpy
     - pip$PY install matplotlib  # For the plot in doc
     - python$PY --version
     - python$PY -c "import torch; print(torch.__version__)"

dockerfile.cpu.test

@@ -60,7 +60,7 @@ RUN mkdir /tmp/openmpi && \
 
 # Install Horovod
 RUN HOROVOD_WITH_TENSORFLOW=1 HOROVOD_WITH_PYTORCH=1 HOROVOD_WITHOUT_MXNET=1 \
-    pip install --no-cache-dir horovod
+    pip install --no-cache-dir horovod==0.19.0
 
 # Install OpenSSH for MPI to communicate between containers
 RUN apt-get install -y --no-install-recommends openssh-client openssh-server && \

dockerfile.gpu.test

@@ -72,7 +72,7 @@ RUN mkdir /tmp/openmpi && \
 # Install Horovod, temporarily using CUDA stubs
 RUN ldconfig /usr/local/cuda/targets/x86_64-linux/lib/stubs && \
     HOROVOD_GPU_ALLREDUCE=NCCL HOROVOD_WITH_TENSORFLOW=1 HOROVOD_WITH_PYTORCH=1 HOROVOD_WITHOUT_MXNET=1 \
-         pip install --no-cache-dir horovod && \
+         pip install --no-cache-dir horovod==0.19.0 && \
     ldconfig
 
 # Install OpenSSH for MPI to communicate between containers