check libdparse & dsymbol with min/max dub version

.gitmodules

@@ -17,3 +17,6 @@
 [submodule "stdx-allocator"]
 	path = stdx-allocator
 	url = https://github.com/dlang-community/stdx-allocator.git
+[submodule "d-test-utils"]
+	path = d-test-utils
+	url = https://github.com/dlang-community/d-test-utils.git

.travis.sh

@@ -3,7 +3,14 @@
 set -e
 
 if [[ $BUILD == dub ]]; then
-    dub test
+    if [[ -n $LIBDPARSE_VERSION ]]; then
+        rdmd ./d-test-utils/test_with_package.d $LIBDPARSE_VERSION libdparse -- dub test
+    elif if [[ -n $DSYMBOL_VERSION ]]; then
+        rdmd ./d-test-utils/test_with_package.d $DSYMBOL_VERSION dsymbol -- dub test
+    else
+        echo 'Cannot run test without LIBDPARSE_VERSION nor DSYMBOL_VERSION environment variable'
+        exit 1
+    fi
 elif [[ $DC == ldc2 ]]; then
     git submodule update --init --recursive
     make test DC=ldmd2

.travis.yml

@@ -10,7 +10,10 @@ os:
 - osx
 env:
 - BUILD=
-- BUILD=dub
+- BUILD=dub LIBDPARSE_VERSION=min
+- BUILD=dub LIBDPARSE_VERSION=max
+- BUILD=dub DSYMBOL_VERSION=min
+- BUILD=dub DSYMBOL_VERSION=max
 branches:
   only:
   - master