Fix test image reference

Author: micrictor

tests/test.sh

@@ -4,7 +4,7 @@
 HERE="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 # Root directory of the repository
 DIST=$(cd "$HERE"/..; pwd)
-IMAGE=${1:-softprops/lambda-rust}
+IMAGE=${1:-rustserverless/lambda-rust}
 
 source "${HERE}"/bashtest.sh