Create a release pipeline on Azure for Windows installer (#7441)

This PR creates a pipeline triggered on tag push matching v0.* (eg. v0.40.0).

Once triggered, this pipeline will build the windows installer, and run integration tests on it, like for the pipeline run nightly.

I also add a simple script to extract from CHANGELOG.md file to extract the relevant part to put it in the body of the GitHub release. I believe it makes things nicer.

* Create release pipeline

* Relax condition on tags

* Put beta keyword

* Update job name

* Fix release pipeline

tools/extract_changelog.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+from __future__ import print_function
+import sys
+import os
+import re
+
+
+CERTBOT_ROOT = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+
+NEW_SECTION_PATTERN = re.compile(r'^##\s*[\d.]+\s*-\s*[\d-]+$')
+
+
+def main():
+    version = sys.argv[1]
+
+    section_pattern = re.compile(r'^##\s*{0}\s*-\s*[\d-]+$'
+                                 .format(version.replace('.', '\\.')))
+
+    with open(os.path.join(CERTBOT_ROOT, 'CHANGELOG.md')) as file_h:
+        lines = file_h.read().splitlines()
+
+    changelog = []
+
+    i = 0
+    while i < len(lines):
+        if section_pattern.match(lines[i]):
+            i = i + 1
+            while i < len(lines):
+                if NEW_SECTION_PATTERN.match(lines[i]):
+                    break
+                changelog.append(lines[i])
+                i = i + 1
+        i = i + 1
+
+    changelog = [entry for entry in changelog if entry]
+
+    print('\n'.join(changelog))
+
+
+if __name__ == '__main__':
+    main()