Revert "Remove esModuleInterop option from tsconfig.json"

This reverts commit e738254.

The current ESLint setup conflicts with itself when using
`import stripAnsi = require('strip-ansi')`, which is what should actually be
used.

tsconfig.json

@@ -4,6 +4,7 @@
     "module": "commonjs",
     "allowJs": true,
     "strict": true,
-    "noEmit": true
+    "noEmit": true,
+    "esModuleInterop": true
   }
 }