chore(package): update aegir to version 21.0.2 (#2778)

Closes #2777

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: Alan Shaw

package.json

@@ -175,7 +175,7 @@
     "yargs-promise": "^1.1.0"
   },
   "devDependencies": {
-    "aegir": "^20.5.1",
+    "aegir": "^21.0.2",
     "base64url": "^3.0.1",
     "clear-module": "^4.0.0",
     "delay": "^4.1.0",