Docker: stop on errors in 3_buildwheels/build.sh

docker/3_buildwheels/build.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -e
+
 # macOS does not support readlink -f, so we use greadlink instead
 if [ $(uname) == 'Darwin' ]; then
     command -v greadlink 2>/dev/null 2>&1 || { echo >&2 "Install greadlink using brew."; exit 1; }