Add gcc4.8 stuff to travis file.

.travis.yml

@@ -50,6 +50,20 @@ matrix:
           packages:
             - g++-5
           sources: *sources
+    - os: linux
+      env: COMPILER=g++-4.8
+      addons:
+        apt:
+          packages:
+            - g++-4.8
+          sources: *sources
+    - os: linux
+      env: COMPILER=g++-4.8 UNICODE_OPTIONS=-DCXXOPTS_USE_UNICODE_HELP=Yes
+      addons:
+        apt:
+          packages:
+            - g++-4.8
+          sources: *sources
     - os: linux
       env: COMPILER=clang++-3.8 CXXFLAGS=-stdlib=libc++
       addons: