Add convenience script to run benchmarks

bench.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+
+# Convenience script to
+# - For a given branch
+# - Run  benchmark tests for a given package
+# - Do the same for master
+# - then compare the two runs with benchcmp
+
+if [ $# -ne 2 ]
+  then
+    echo "USAGE: ./bench.sh <git-branch> <package-to-bench>"
+    exit 1
+fi
+
+
+BRANCH=$1
+PACKAGE=$2
+
+git checkout $BRANCH
+go test -test.run=NONE -bench=".*" -test.benchmem=true ./$PACKAGE > /tmp/bench-$PACKAGE-$BRANCH.txt
+
+git checkout master
+go test -test.run=NONE -bench=".*" -test.benchmem=true ./$PACKAGE > /tmp/bench-$PACKAGE-master.txt
+
+
+benchcmp /tmp/bench-$PACKAGE-master.txt /tmp/bench-$PACKAGE-$BRANCH.txt