Use https in redirect rules (#1939)

Fixes #1937

Author: chalin

firebase.json

@@ -62,7 +62,7 @@
       { "source": "/articles/m*{,/**}", "destination": "/articles", "type": 301 },
       { "source": "/assets/dart-logo-for-shares*.png", "destination": "/assets/shared/dart-logo-for-shares.png?2", "type": 301 },
       { "source": "/assets/dart-logo-wordmark*.png", "destination": "/assets/shared/dart-logo-for-shares.png?2", "type": 301 },
-      { "source": "/atom.xml", "destination": "http://news.dartlang.org/feeds/posts/default", "type": 301 },
+      { "source": "/atom.xml", "destination": "https://news.dartlang.org/feeds/posts/default", "type": 301 },
       { "source": "/authors/bob-nystrom?(.html)", "destination": "/resources/authors/bob-nystrom", "type": 301 },
       { "source": "/authors/florian-loitsch?(.html)", "destination": "/resources/authors/florian-loitsch", "type": 301 },
       { "source": "/authors/gilad-bracha?(.html)", "destination": "/resources/authors/gilad-bracha", "type": 301 },
@@ -137,7 +137,7 @@
       { "source": "/install", "destination": "/get-dart", "type": 301 },
       { "source": "/language-tour", "destination": "/guides/language/language-tour", "type": 301 },
       { "source": "/logos", "destination": "https://github.com/dart-lang/logos", "type": 301 },
-      { "source": "/linter/lints/:lint*", "destination": "http://dart-lang.github.io/linter/lints/:lints*", "type": 301 },
+      { "source": "/linter/lints/:lint*", "destination": "https://dart-lang.github.io/linter/lints/:lints*", "type": 301 },
       { "source": "/mailing-list", "destination": "https://groups.google.com/a/dartlang.org/forum/#!forum/misc", "type": 301 },
       { "source": "/news{,/**}", "destination": "https://news.dartlang.org/", "type": 301 },
       { "source": "/observatory{,/**}", "destination": "https://dart-lang.github.io/observatory", "type": 301 },