patch 8.1.1504: sound test still fails on Travis

Problem:    Sound test still fails on Travis.
Solution:   Add more lines to the install section.

Author: brammool

.travis.yml

@@ -10,6 +10,9 @@ compiler:
   - gcc
 
 env:
+  global:
+      # pretend to play sounds
+      AUDIODEV=null
   - &tiny-nogui
     BUILD=yes TEST=test COVERAGE=no FEATURES=tiny "CONFOPT='--disable-gui'" SHADOWOPT= SRCDIR=./src CHECK_AUTOCONF=no
   - &tiny
@@ -121,15 +124,23 @@ before_install:
     if [[ "${TRAVIS_OS_NAME}" = "linux" ]] && [[ "${CC}" = "clang" ]]; then
       ln -sf "$(which llvm-cov)" /home/travis/bin/gcov
     fi
+  # Should make sound work (might not all be needed)
+  - |
+    if [[ "${TRAVIS_OS_NAME}" = "linux" ]]; then
+      sudo apt-get update -qq
+      sudo usermod -a -G audio travis
+      sudo apt-get install -y portaudio19-dev
+      sudo apt-get install -y libasound2-dev alsa-utils alsa-oss
+      sudo bash test/prep-dummy-soundcard.sh
+      sudo apt-get install -y lame
+    fi
 
 before_script:
   # Start virtual framebuffer to be able to test the GUI. Does not work on OS X.
   - |
     if [[ "${TRAVIS_OS_NAME}" = "linux" ]]; then
       export DISPLAY=:99.0
       sh -e /etc/init.d/xvfb start && sleep 3
-      # pretend to play sounds
-      export AUDIODEV=null
     fi
 
 script:

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1504,
 /**/
     1503,
 /**/