Add python3.6 and python3.7 support in padde build scripts

test=develop

Author: velconia

paddle/scripts/paddle_build.sh

@@ -116,6 +116,18 @@ function cmake_gen() {
                 export PYTHON_FLAGS="-DPYTHON_EXECUTABLE:FILEPATH=/opt/_internal/cpython-3.5.1/bin/python3
             -DPYTHON_INCLUDE_DIR:PATH=/opt/_internal/cpython-3.5.1/include/python3.5m
             -DPYTHON_LIBRARIES:FILEPATH=/opt/_internal/cpython-3.5.1/lib/libpython3.so"
+            elif [ "$1" == "cp36-cp36m" ]; then
+                export LD_LIBRARY_PATH=/opt/_internal/cpython-3.6.0/lib/:${LD_LIBRARY_PATH}
+                export PATH=/opt/_internal/cpython-3.6.0/bin/:${PATH}
+                export PYTHON_FLAGS="-DPYTHON_EXECUTABLE:FILEPATH=/opt/_internal/cpython-3.6.0/bin/python3
+            -DPYTHON_INCLUDE_DIR:PATH=/opt/_internal/cpython-3.6.0/include/python3.6m
+            -DPYTHON_LIBRARIES:FILEPATH=/opt/_internal/cpython-3.6.0/lib/libpython3.so"
+            elif [ "$1" == "cp37-cp37m" ]; then
+                export LD_LIBRARY_PATH=/opt/_internal/cpython-3.7.0/lib/:${LD_LIBRARY_PATH}
+                export PATH=/opt/_internal/cpython-3.7.0/bin/:${PATH}
+                export PYTHON_FLAGS="-DPYTHON_EXECUTABLE:FILEPATH=/opt/_internal/cpython-3.7.0/bin/python3
+            -DPYTHON_INCLUDE_DIR:PATH=/opt/_internal/cpython-3.7.0/include/python3.7m
+            -DPYTHON_LIBRARIES:FILEPATH=/opt/_internal/cpython-3.7.0/lib/libpython3.so"
            fi
         fi
     fi
@@ -419,7 +431,7 @@ function assert_api_not_changed() {
     source .env/bin/activate
     pip install ${PADDLE_ROOT}/build/python/dist/*whl
     python ${PADDLE_ROOT}/tools/print_signatures.py paddle.fluid > new.spec
-    if [ "$1" == "cp35-cp35m" ]; then
+    if [ "$1" == "cp35-cp35m" ] || [ "$1" == "cp36-cp36m" ] || [ "$1" == "cp37-cp37m" ]; then
         # Use sed to make python2 and python3 sepc keeps the same
         sed -i 's/arg0: str/arg0: unicode/g' new.spec
         sed -i "s/\(.*Transpiler.*\).__init__ ArgSpec(args=\['self'].*/\1.__init__ /g" new.spec