Check for trailing whitespace during CI

.travis.yml

@@ -3,9 +3,12 @@ node_js:
 - 4
 
 before_install:
-# building vere directly in lieu of a working debian package script
 # pwd: ~/urbit/arvo
-- cd ../
+- cd .travis/
+- bash check-trailing-whitespace.sh
+- cd ../../
+# pwd: ~/urbit
+# building vere directly in lieu of a working debian package script
 - wget https://github.com/ninja-build/ninja/releases/download/v1.8.2/ninja-linux.zip
 - unzip ninja-linux.zip
 - sudo mv ninja /usr/bin/

.travis/check-trailing-whitespace.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+whitespace=$(find .. -path ../.git -prune -o \
+             -type f -exec egrep -l " +$" {} \;);
+
+if [ ! -z $whitespace ]
+then
+  echo 'found trailing whitespace in:';
+  echo $whitespace;
+  exit 1;
+fi