Update .travis.yml from master.

.travis.yml

@@ -1,10 +1,16 @@
 language: c
-matrix:
-    include:
-        - compiler: gcc
-        - compiler: clang
-          env: CFLAGS="-g -O2"
+
+os:
+    - linux
+    - osx
+
+compiler:
+    - gcc
+    - clang
+
 before_install:
-    - sudo apt-get update -qq
-    - sudo apt-get -y install bison debhelper autotools-dev dh-autoreconf file libncurses5-dev libevent-dev pkg-config libutempter-dev build-essential
-script: (CFLAGS= ./autogen.sh) && ./configure --enable-debug && make
+    - if [ "$TRAVIS_OS_NAME" = "linux" ]; then sudo apt-get update -qq; fi
+    - if [ "$TRAVIS_OS_NAME" = "linux" ]; then sudo apt-get -y install bison autotools-dev libncurses5-dev libevent-dev pkg-config libutempter-dev build-essential; fi
+
+script:
+    - ./autogen.sh && ./configure && make