Octave: remove use of ppa:kwwette/octaves

.travis.yml

@@ -322,11 +322,6 @@ matrix:
       env: SWIGLANG=java CPP11=1
       sudo: required
       dist: xenial
-    - compiler: gcc
-      os: linux
-      env: SWIGLANG=octave SWIGJOBS=-j2 VER=4.4 CPP11=1
-      sudo: required
-      dist: trusty
     - os: linux
       env: SWIGLANG=python CPP11=1
       sudo: required

Tools/travis-linux-install.sh

@@ -71,21 +71,7 @@ case "$SWIGLANG" in
 		travis_retry sudo apt-get -qq install ocaml camlp4
 		;;
 	"octave")
-		if [[ -z "$VER" ]]; then
 		travis_retry sudo apt-get -qq install liboctave-dev
-		else
-			# Travis adds external PPAs which contain newer versions of packages
-			# than in baseline trusty. These newer packages prevent some of the
-			# Octave packages in ppa:kwwette/octave, which rely on the older
-			# packages in trusty, from installing. To prevent these kind of
-			# interactions arising, clean out all external PPAs added by Travis
-			# before installing Octave
-			sudo rm -rf /etc/apt/sources.list.d/*
-			travis_retry sudo apt-get -qq update
-			travis_retry sudo add-apt-repository -y ppa:kwwette/octaves
-			travis_retry sudo apt-get -qq update
-			travis_retry sudo apt-get -qq install liboctave${VER}-dev
-		fi
 		;;
 	"php")
 		travis_retry sudo add-apt-repository -y ppa:ondrej/php