chore(package): update aegir to version 20.0.0

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
     "through2": "^3.0.0"
   },
   "devDependencies": {
-    "aegir": "^19.0.3"
+    "aegir": "^20.0.0"
   },
   "contributors": [
     "Alan Shaw <alan.shaw@protocol.ai>",