Use HTTPS in fullUrl by default for resources

Since no redirect or HSTS is in place, these downloads are
vulnerable to being MitM'd. This commit changes all future
links to use "HTTPS" in the protocol part instead of "HTTP".

Related: scala/scala-lang#627

Author: Adam Williams

src/main/scala/MakeDownloadPage.scala

@@ -37,7 +37,7 @@ class MakeDownloadPage(version: String, releaseDate: Date = new Date()) {
 
   def resourceArchive(cls: String, name: String, ext: String, desc: String): Future[String] = {
     val fileName = s"$name-$version.$ext"
-    val fullUrl = s"http://downloads.lightbend.com/scala/$version/$fileName"
+    val fullUrl = s"https://downloads.lightbend.com/scala/$version/$fileName"
     resource(cls, fileName, desc, fullUrl)
   }