travis: Update config file

Use 'script' instead of 'install' to specify build command.
Add linux build option with udev disabled.

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
diff --git a/.travis.yml b/.travis.yml
index 59eba91..fe1b361 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,9 +10,8 @@
     - osx
 
 before_install:
-    - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then apt-get install -qq libudev-dev ; fi
+    - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then apt-get update -qq && apt-get install -qq libudev-dev; fi
 
-install:
-    - ./autogen.sh
-    - ./configure
-    - make -j4
+script:
+    - ./autogen.sh && make -j4
+    - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then ./autogen.sh --disable-udev && make -j4; fi