Add debug tools to .travis.yml

Author: danpoe

.travis.yml

@@ -96,11 +96,13 @@ jobs:
             - g++-5
             - libubsan0
             - parallel
+            - gdb
+            - valgrind
       before_install:
         - mkdir bin
         - ln -s /usr/bin/gcc-5 bin/gcc
         - ln -s /usr/bin/g++-5 bin/g++
-      # env: COMPILER=g++-5 SAN_FLAGS="-fsanitize=undefined -fno-sanitize-recover -fno-omit-frame-pointer"
+      # env: COMPILER=g++-5 SAN_FLAGS="-fsanitize=undefined -fno-sanitize-recover -fno-omit-frame-pointer -g"
       env:
         - COMPILER="ccache /usr/bin/g++-5"
         - EXTRA_CXXFLAGS="-D_GLIBCXX_DEBUG"