Sort package keys before output

Package managers ususally sort package keys alphabetically. If you newly
inherit then you may get a bunch of additions which will then be
unalphabatized, leading to a messy diff if a new package is added with
the package manager.

src/generateInheritedPackageJson.ts

@@ -70,7 +70,7 @@ function shouldUpdate(mine: any, theirs: any) {
   let result = false;
 
   for (const [key, value] of Object.entries(theirs)) {
-    if (mine[key] !== value) {
+    if (!mine || mine[key] !== value) {
       result = true;
     }
   }

src/updateCommand.ts

@@ -15,8 +15,10 @@ export function updateCommand(cwd: string) {
       // Sort dependencies before outputing them like package managers do
       ['dependencies', 'devDependencies'].map(function(key){
         if (output[key]) {
-          const keys = Object.keys(output[key]).sort();
-          output[key] = JSON.parse(JSON.stringify(output[key], keys));
+          output[key] = Object.keys(output[key]).sort().reduce(function(newObject, packageName) {
+            newObject[packageName] = output[key][packageName];
+            return newObject;
+          }, {});
         }
       });
       fs.writeFileSync(