Update and dedupe bluebird to the latest

Update and dedupe bluebird to the latest

$ npm list bluebird
gitter-webapp@19.2.0 C:\Users\MLM\Documents\GitLab\webapp
+-- @gitterhq/env@0.47.0
| +-- bluebird@3.7.2  deduped
| `-- ioredis@1.15.1
|   `-- bluebird@2.11.0
+-- bluebird@3.7.2
+-- cypress@4.8.0
| `-- bluebird@3.7.2
+-- gitter-markdown-processor@21.0.0
| `-- bluebird@3.7.2
+-- gitter-realtime-client@2.2.0
| `-- halley@0.7.0
|   `-- bluebird@3.7.2  deduped
+-- intercom-client@2.9.4
| `-- bluebird@3.7.2  deduped
+-- mongoose@4.6.8
| `-- mquery@2.0.0
|   `-- bluebird@2.10.2
+-- octonode@0.9.5
| `-- bluebird@3.7.2  deduped
+-- tentacles@0.8.0
| `-- bluebird@3.7.2  deduped
+-- vue-jest@4.0.0-beta.2
| `-- @vue/component-compiler-utils@2.6.0
|   `-- consolidate@0.15.1
|     `-- bluebird@3.7.2  deduped
+-- UNMET PEER DEPENDENCY webpack@4.29.0
| `-- terser-webpack-plugin@1.4.5
|   `-- cacache@12.0.4
|     `-- bluebird@3.7.2  deduped
`-- webpack-bundle-analyzer@3.5.2
  `-- bfj@6.1.2
    `-- bluebird@3.7.2  deduped