Fix ts config

Recently a change was made to add `declaration: true` to the `tsconfig.json`.  This option generates the corresponding `d.ts` typing files.  The `allowJs` option cannot be used with this new option, so it is being remove.  We don’t actually need to directly compile js files, anyway, so this should affect nothing.

Author: marshallswain

tsconfig.json

@@ -1,6 +1,5 @@
 {
   "compilerOptions": {
-    "allowJs": true,
     "allowSyntheticDefaultImports": true,
     "esModuleInterop": true,
     "outDir": "dist",
@@ -9,11 +8,6 @@
     "target": "es6",
     "sourceMap": false
   },
-  "include": [
-    "src/**/*"
-  ],
-  "exclude": [
-    "node_modules",
-    "**/*.test.js"
-  ]
-}
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "**/*.test.js"]
+}