Add autopoint to packages list

This change adds the necessary packages to install the autopoint binary
on both Ubuntu and OSX. This is necessary since the build needs the
gettext utilities.

Also remove the installation for realpath, since we are no longer
building for Trusty.

.travis.yml

@@ -32,13 +32,11 @@ addons:
         packages:
         - libusb-1.0-0-dev
         - libudev-dev
+        - autopoint
     homebrew:
         packages:
         - libusb
-
-# Ensure realpath is available on Trusty
-before_script:
-    - if [ $TRAVIS_OS_NAME = linux ]; then sudo apt-get install realpath || true; fi
+        - gettext
 
 # Enable parallel make
 env: