Add cppclean as static analysis job for Travis-CI (#43)

close #18

.travis.yml

@@ -40,6 +40,14 @@ matrix:
         - brew install gettext
         - export PATH="/usr/local/opt/gettext/bin:$PATH"
         - export WITH_SDL2="ON"
+    - os: linux
+      name: "Static analysis"
+      script:
+        - export EXCLUDE_PATTERN_1=" not found in expected header ";
+        - export EXCLUDE_PATTERN_2=" does not need to be \#included; use a forward declaration instead";
+        - export EXCLUDE_PATTERN_3=" not found in any directly \#included header";
+        - git clone https://github.com/myint/cppclean;
+        - ./cppclean/cppclean src | grep -v "$EXCLUDE_PATTERN_1" | grep -v "$EXCLUDE_PATTERN_2" | grep -v "$EXCLUDE_PATTERN_3";
 
 script:
   - |