install requirements-dev.txt on manylinux1

(cherry picked from commit 752e783884c4b0f7e6eac1d0aed47f8c60cbdb7f)

dockerfiles/buildwheel.sh

@@ -6,6 +6,7 @@ echo "arch=$ARCH"
 
 for V in cp36-cp36m cp35-cp35m cp34-cp34m cp27-cp27m cp27-cp27mu; do
     PYBIN=/opt/python/$V/bin
-    rm -rf build/       # Avoid lib build by narrow Python is used by wide python
+    rm -rf build src/cchardet/__pycache__ src/cchardet/*.cpp src/cchardet/*.pyc src/cchardet/*.so src/cchardet.egg-info src/tests/__pycache__ src/tests/*.pyc
+    $PYBIN/pip install -r requirements-dev.txt
     $PYBIN/python setup.py bdist_wheel -p manylinux1_${ARCH}
 done