Become a monorepo with yarn workspaces and lerna

Make room to have multiple javascript projects in this repository,
using yarn workspaces and lerna as project manager.

Add a separata package.json for the plugin frontend. Because of the
way Kolibri plugins work, this workspace can't go to the packages/
folder.

Add a lerna configuration file and adapt the package.json with the
same workspaces listed. Also, require yarn in the package.json engine
because that's what we are using.

https://phabricator.endlessm.com/T31931

Author: manuq

kolibri_explore_plugin/assets/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "discovery-page",
+  "description": "A replacement for kolibri's Learn tab.",
+  "private": true,
+  "version": "1.0.0",
+  "dependencies": {
+    "kolibri-design-system": "https://github.com/learningequality/kolibri-design-system"
+  },
+  "devDependencies": {
+    "kolibri-tools": "0.14.5-dev.4"
+  }
+}

lerna.json

@@ -0,0 +1,9 @@
+{
+  "packages": [
+    "kolibri_explore_plugin/assets",
+    "packages/*"
+  ],
+  "version": "independent",
+  "npmClient": "yarn",
+  "useWorkspaces": true
+}

package.json

@@ -1,22 +1,23 @@
 {
+  "name": "eos-discovery",
+  "description": "Monorepo with kolibri's Discovery page and custom channel presentations.",
+  "private": true,
   "scripts": {
     "build": "kolibri-tools build prod --plugins kolibri_explore_plugin",
     "clean": "kolibri-tools build clean --plugins kolibri_explore_plugin",
     "dev": "kolibri-tools build dev --plugins kolibri_explore_plugin --port 4000",
     "lint-frontend": "kolibri-tools lint -p 'kolibri_explore_plugin/assets/**/*.{js,vue,scss,less,css}'",
     "lint-frontend:format": "yarn run lint-frontend --write"
   },
-  "name": "kolibri-explore-render-plugin",
-  "description": "Explore Plugin for Kolibri",
-  "private": true,
-  "dependencies": {
-    "kolibri-design-system": "https://github.com/learningequality/kolibri-design-system"
-  },
+  "workspaces": [
+    "kolibri_explore_plugin/assets",
+    "packages/*"
+  ],
   "devDependencies": {
-    "kolibri-tools": "0.14.5-dev.4"
+    "lerna": "^4.0.0"
   },
   "engines": {
     "node": "10.x",
-    "npm": ">= 3"
+    "yarn": "1.x"
   }
 }