Add ability to query beta vs stable

Author: zheng

entrypoint.py

@@ -11,7 +11,11 @@
 releases = repo.get_releases()
 for release in releases:
     if wanted_release == 'stable':
-        if release.prerelease == 0 and release.draft == 0:
+        if release.prerelease == 0 and release.draft == 0 and release.body == "Warp Stable release":
+            print('::set-output name=release::{}'.format(release.tag_name))
+            break
+    elif wanted_release == 'beta':
+        if release.prerelease == 0 and release.draft == 0 and release.body == "Warp Beta release":
             print('::set-output name=release::{}'.format(release.tag_name))
             break
     elif wanted_release == 'prerelease':