[BUGFIX] Fix composer run command in build script (#160)

* [BUGFIX] Fix composer run command in build script

* [BUGFIX] Fix permissions for make build composer

Runs the composer docker container with the current users uid/gid,
otherwise composer writes all files as root user.

Setting the composer cache dir (inside the container) to /tmp
avoids multiple 'Cannot create cache directory'-warnings
while the original composer cache dir is only writeable by root.

Author: tbal

Diff for: bin/build.sh

@@ -20,7 +20,7 @@ sectionHeader "Checking for composer.json ..."
 find "$CODE_DIR" -type f -name 'composer.json' | excludeFilter | while read FILE; do
     COMPOSER_JSON_DIR=$(dirname $($READLINK -f "$FILE"))
 
-    execInDir "$COMPOSER_JSON_DIR" "composer install --no-dev --no-interaction"
+    execInDir "$COMPOSER_JSON_DIR" "docker run --rm --env COMPOSER_CACHE_DIR=/tmp --user $(id -u):$(id -g) -v \$(pwd):/app composer/composer:alpine install --no-dev --no-interaction"
 done