Added API validation of instance filter names. Fixes https://trello.com/c/VH9Vnd8z

tools/scripts/get_ec2_filter_names.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+
+import json
+import sys
+import requests
+from bs4 import BeautifulSoup
+
+response = requests.get('http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInstances.html')
+soup = BeautifulSoup(response.text)
+
+section_h3 = soup.find(id='query-DescribeInstances-filters')
+section_div = section_h3.find_parent('div', attrs={'class': 'section'})
+
+filter_names = []
+for term in section_div.select('div.variablelist dt span.term'):
+    filter_name = term.get_text()
+    if not filter_name.startswith('tag:'):
+        filter_names.append(filter_name)
+filter_names.sort()
+
+json.dump(filter_names, sys.stdout, indent=4)