Include Slack webhook example script

README.md

@@ -209,3 +209,11 @@ $ detect-secrets-server scan yelp/detect-secrets \
 	--output-hook pysensu \
 	--output-config examples/pysensu.config.yaml
 ```
+
+#### Slack
+
+For Python 3 users, you can utilize the example Slack webhook script under 
+`examples/slack_webhook.py`. You'll need to add a `config.ini` with your Slack webhook 
+URL. This pretty formats the JSON and also builds a direct URL to the repos to help quickly
+review. You'll need to add the [slack_webhook dependency](https://pypi.org/project/slack-webhook/). 
+```

examples/slack_webhook.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3.6		            '
+"""
+Sample config.ini
+[Slack]
+webhook = https://hooks.slack.com/services/TXXXXX/BXXXXX
+"""
+import configparser
+import json
+import sys
+
+from slack_webhook import Slack
+
+
+def main():
+    # leaving this so cron picks up this output as doublecheck
+    print('repo:', sys.argv[1])
+    print(json.dumps(json.loads(sys.argv[2]), indent=2, sort_keys=True))
+
+    # pull Slack webhook out of config file
+    # Use ConfigParser to build necessary secrets for integrations
+    config = configparser.ConfigParser()
+    config.read('config.ini')
+    slack = Slack(url=config['Slack']['webhook'])
+
+    # build variables for this wacky json
+    # there'll only ever be one repo
+    repo = sys.argv[1]
+    payload = json.loads(sys.argv[2])
+
+    filepaths = list(payload.keys())
+    for filepath in filepaths:
+        instances = payload[filepath]
+        for instance in instances:
+            author = instance['author']
+            commit = instance['commit']
+            detected_type = instance['type']
+            line_number = instance['line_number']
+
+            # build the message using Slack's "legacy" attachment
+            slack.post(text="<insert funny gerblin gibberish>",
+                       attachments=[{
+                           "fallback": "Required plain-text summary of the attachment.",
+                           "color": "#36a64f",
+                           "title": "repo: {}".format(repo),
+                           "title_link": "https://www.github.com/{}/blob/{}/{}#L{}".format(repo, commit, filepath, line_number),
+                           "text": "File: {}".format(filepath),
+                           "fields": [
+                               {
+                                   "title": "Type",
+                                   "value": detected_type,
+                                   "short": "true"
+                               },
+                               {
+                                   "title": "Author",
+                                   "value": author,
+                                   "short": "true"
+                               }, {
+                                   "title": "Commit",
+                                   "value": commit,
+                                   "short": "false"
+                               }
+                           ]
+                       }]
+                       )
+
+
+if __name__ == '__main__':
+    main()