Initialize a Lerna project

Lerna seems like a reasonable place to start:
- One repository for easier cross-team work and one place for issues
- Multiple packages for independent versioning

lerna.json

@@ -0,0 +1,6 @@
+{
+  "packages": [
+    "packages/*"
+  ],
+  "version": "independent"
+}

package.json

@@ -0,0 +1,7 @@
+{
+  "name": "root",
+  "private": true,
+  "devDependencies": {
+    "lerna": "^3.13.3"
+  }
+}