add script/test for running tests

Instruct it to fail on Ruby syntax warnings coming from only the code in
this project.

.travis.yml

@@ -1,3 +1,5 @@
+script: script/test
+language: ruby
 rvm:
   - 1.8.7
   - 1.9.2

hub.gemspec

@@ -17,6 +17,7 @@ Gem::Specification.new do |s|
   s.files            += Dir.glob("lib/**/*")
   s.files            += Dir.glob("bin/**/*")
   s.files            += Dir.glob("man/**/*")
+  s.files            += Dir.glob("script/**/*")
   s.files            += Dir.glob("test/**/*")
 
   s.executables       = %w( hub )

script/test

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+set -e
+
+STATUS=0
+warnings="${TMPDIR:-/tmp}/hub-warnings.$$"
+
+run() {
+  # Save warnings on stderr to a separate file
+  RUBYOPT="$RUBYOPT -w" bundle exec "$@" \
+    2> >(tee >(grep 'warning:' >>"$warnings") | grep -v 'warning:') || STATUS=$?
+}
+
+check_warnings() {
+  # Display Ruby warnings from this project's source files. Abort if any were found.
+  num="$(grep -F "$PWD" "$warnings" | grep -v "${PWD}/bundle" | sort | uniq -c | sort -rn | tee /dev/stderr | wc -l)"
+  rm -f "$warnings"
+  if [ "$num" -gt 0 ]; then
+    echo "FAILED: this test suite doesn't tolerate Ruby syntax warnings!" >&2
+    exit 1
+  fi
+}
+
+run rake test
+run cucumber features
+
+check_warnings
+
+exit $STATUS