Move github release checking to node.js

Our upload script was relying on an old python script to find the GitHub release for uploading.

script/find-release.js

@@ -0,0 +1,37 @@
+const GitHub = require('github')
+const github = new GitHub()
+
+if (process.argv.length < 3) {
+  console.log('Usage: find-release version')
+  process.exit(1)
+}
+
+const version = process.argv[2]
+
+async function findRelease () {
+  github.authenticate({type: 'token', token: process.env.ELECTRON_GITHUB_TOKEN})
+  let releases = await github.repos.getReleases({
+    owner: 'electron',
+    repo: 'electron'
+  })
+  let targetRelease = releases.data.find(release => {
+    return release.tag_name === version
+  })
+  let returnObject = {}
+
+  if (targetRelease) {
+    returnObject = {
+      id: targetRelease.id,
+      draft: targetRelease.draft,
+      exists: true
+    }
+  } else {
+    returnObject = {
+      exists: false,
+      draft: false
+    }
+  }
+  console.log(JSON.stringify(returnObject))
+}
+
+findRelease()