fix travis tests: use https for downloading sources

diff --git a/composer.json b/composer.json
index 3a1f028..a4c27d4 100644 (file)
--- a/composer.json
+++ b/composer.json
@@ -33,7 +33,7 @@
                 "name": "docbook/docbook-xsl",
                 "version": "1.78.1",
                 "dist": {
-                    "url": "http://sourceforge.net/projects/docbook/files/docbook-xsl/1.78.1/docbook-xsl-1.78.1.zip/download",
+                    "url": "https://sourceforge.net/projects/docbook/files/docbook-xsl/1.78.1/docbook-xsl-1.78.1.zip/download",
                     "type": "zip"
                 }
             }