Merge pull request #12 from php-etl/fix/lock-contracts-versions

fix lock contracts version to get new minor versions

Author: JoMessina

composer.json

@@ -30,7 +30,7 @@
         "ext-simplexml": "*",
         "php-etl/bucket": "*",
         "box/spout": "^3.1",
-        "php-etl/pipeline-contracts": "0.4.0",
+        "php-etl/pipeline-contracts": "0.4.*",
         "psr/log": "^3.0"
     },
     "require-dev": {