Test multiple versions of D on Travis.

2.081 is reportedly broken and 2.086 was tested and fixed in #1594.

.travis.yml

@@ -54,7 +54,12 @@ matrix:
       dist: xenial
     - compiler: gcc
       os: linux
-      env: SWIGLANG=d
+      env: SWIGLANG=d VER=2.066.0
+      sudo: required
+      dist: xenial
+    - compiler: gcc
+      os: linux
+      env: SWIGLANG=d VER=2.086.1
       sudo: required
       dist: xenial
     - compiler: gcc
@@ -458,6 +463,12 @@ matrix:
       osx_image: xcode10.2
 
   allow_failures:
+    # Newer version of D not yet working/supported
+    - compiler: gcc
+      os: linux
+      env: SWIGLANG=d VER=2.086.1
+      sudo: required
+      dist: xenial
     # seg fault in director_basic testcase
     - compiler: gcc
       os: linux

Tools/travis-linux-install.sh

@@ -23,8 +23,8 @@ case "$SWIGLANG" in
 		travis_retry sudo apt-get -qq install mono-devel
 		;;
 	"d")
-		travis_retry wget http://downloads.dlang.org/releases/2014/dmd_2.066.0-0_amd64.deb
-		travis_retry sudo dpkg -i dmd_2.066.0-0_amd64.deb
+		travis_retry wget http://downloads.dlang.org/releases/2.x/${VER}/dmd_${VER}-0_amd64.deb
+		travis_retry sudo dpkg -i dmd_${VER}-0_amd64.deb
 		;;
 	"go")
 		if [[ "$VER" ]]; then