Update documentation on new env vars (#24)

docs/installation.md

@@ -41,7 +41,11 @@ your Barometer, then show various deployment options at your disposal.
     | GCP Project ID | BB_PROJECT_ID  | <span class="label label-red">Deprecated</span> The Google Cloud Project ID (GCP) for easy-access of GCP resources. This will be deprecated in the first major release.                                                                                                                                              |
     | Table          | BB_TABLE       | The database connection URL to store Barometer logs. For Bigquery, use the `bq` protocol like so: `bq://my-gcp-project.my-dataset.my-table`                                                                                                                          |
     | Slack Token    | BB_SLACK_TOKEN | The Slack Token generated whenever you create an App. This is used to verify that the incoming request came from the authorized account. See this [page](https://slack.com/intl/en-ph/help/articles/215770388-Create-and-regenerate-API-tokens) for more information |
-    | Area           | BB_AREA        | <span class="label label-red">Deprecated</span> The IANA compliant area for correcting the timezone. For example, `Asia/Manila`. This will be deprecated in the first major release.                                                                                                                                 |
+    | Area           | BB_AREA        | <span class="label label-red">Deprecated</span> The IANA compliant area for correcting the timezone. For example, `Asia/Manila`. This will be deprecated in the first major release. |
+    |Twitter Consumer Key | BB_TWITTER_CONSUMER_KEY | *(Optional)* Your Twitter Consumer Key to fetch Tweets from [tinycarebot](https://twitter.com/tinycarebot). Check [this link](https://dev.twitter.com/apps/new) for details |
+    | Twitter Consumer Secret| BB_TWITTER_CONSUMER_SECRET        | *(Optional)* Your Twitter Consumer Secret to fetch Tweets from [tinycarebot](https://twitter.com/tinycarebot). Check [this link](https://dev.twitter.com/apps/new) for details |
+    | Twitter Access Key| BB_TWITTER_ACCESS_KEY        | *(Optional)* Your Twitter Access Key to fetch Tweets from [tinycarebot](https://twitter.com/tinycarebot). Check [this link](https://dev.twitter.com/apps/new) for details |
+    | Twitter Access Secret| BB_TWITTER_ACCESS_SECRET        | *(Optional)* Your Twitter Access Secret to fetch Tweets from [tinycarebot](https://twitter.com/tinycarebot). Check [this link](https://dev.twitter.com/apps/new) for details |
 
     You can find more information about the `init` command by running
     `barometer init --help`.