Merge pull request #783 from Shopify/dependabot/npm_and_yarn/koa-2.15.4

Bump koa from 2.15.3 to 2.15.4

Author: graygilmore

yarn.lock

@@ -4223,9 +4223,9 @@ koa-static@^5.0.0:
     koa-send "^5.0.0"
 
 koa@^2.15.3:
-  version "2.15.3"
-  resolved "https://registry.npmjs.org/koa/-/koa-2.15.3.tgz#062809266ee75ce0c75f6510a005b0e38f8c519a"
-  integrity sha512-j/8tY9j5t+GVMLeioLaxweJiKUayFhlGqNTzf2ZGwL0ZCQijd2RLHK0SLW5Tsko8YyyqCZC2cojIb0/s62qTAg==
+  version "2.16.0"
+  resolved "https://registry.yarnpkg.com/koa/-/koa-2.16.0.tgz#0a82ed4d460774ff0b444e361cd6e4bd5c767ee3"
+  integrity sha512-Afhqq0Vq3W7C+/rW6IqHVBDLzqObwZ07JaUNUEF8yCQ6afiyFE3RAy+i7V0E46XOWlH7vPWn/x0vsZwNy6PWxw==
   dependencies:
     accepts "^1.3.5"
     cache-content-type "^1.0.0"