Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into gfortran

.pre-commit-config.yaml

 -   repo: https://github.com/Lucas-C/pre-commit-hooks.git
-    sha: c25201a00e6b0514370501050cf2a8538ac12270
+    sha: v1.0.1
     hooks:
     -   id: remove-crlf
         files: (?!.*third_party)^.*$ | (?!.*book)^.*$
 -   repo: https://github.com/reyoung/mirrors-yapf.git
     sha: v0.13.2
     hooks:
-    - id: yapf
-      files: (.*\.(py|bzl)|BUILD|.*\.BUILD|WORKSPACE)$
+    -   id: yapf
+        files: (.*\.(py|bzl)|BUILD|.*\.BUILD|WORKSPACE)$
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    sha: 7539d8bd1a00a3c1bfd34cdb606d3a6372e83469
+    sha: 5bf6c09bfa1297d3692cadd621ef95f1284e33c0
     hooks:
     -   id: check-added-large-files
     -   id: check-merge-conflict

Dockerfile

@@ -46,6 +46,11 @@ RUN pip install --upgrade pip && \
     pip install pre-commit 'requests==2.9.2' 'ipython==5.3.0' && \
     pip install 'ipykernel==4.6.0' 'jupyter==1.0.0'
 
+# To fix https://github.com/PaddlePaddle/Paddle/issues/1954, we use
+# the solution in https://urllib3.readthedocs.io/en/latest/user-guide.html#ssl-py2
+RUN apt-get install -y libssl-dev libffi-dev
+RUN pip install certifi urllib3[secure]
+
 RUN curl -sSL https://cmake.org/files/v3.4/cmake-3.4.1.tar.gz | tar -xz && \
     cd cmake-3.4.1 && ./bootstrap && make -j `nproc` && make install && \
     cd .. && rm -rf cmake-3.4.1