feat(build): use babel (#3825)

.babelrc

.vscode/launch.json

lib/platform/azure/index.js

lib/platform/bitbucket-server/index.ts

lib/platform/bitbucket/index.ts

lib/platform/bitbucket/utils.ts

lib/platform/git/storage.ts

lib/platform/github/index.js

lib/platform/gitlab/index.js

lib/renovate.ts

package.json

test/platform/azure/index.spec.js

test/platform/bitbucket-server/index.spec.ts

test/platform/bitbucket/index.spec.ts

test/platform/github/index.spec.js

test/platform/gitlab/index.spec.js

tsconfig.app.json

tsconfig.json

yarn.lock