Add Travis support

scripts/install-boost.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+# Assumptions:
+# 1) BOOST_ROOT and BOOST_URL are already defined,
+# and contain valid values.
+# 2) The last namepart of BOOST_ROOT matches the
+# folder name internal to boost's .tar.gz
+# When testing you can force a boost build by clearing travis caches:
+# https://travis-ci.org/ripple/rippled/caches
+set -e
+if [ ! -d "$BOOST_ROOT/lib" ]
+then
+  wget $BOOST_URL -O /tmp/boost.tar.gz
+  cd `dirname $BOOST_ROOT`
+  rm -fr ${BOOST_ROOT}
+  tar xzf /tmp/boost.tar.gz
+  params="define=_GLIBCXX_USE_CXX11_ABI=0 --with-program_options --with-system"
+  cd $BOOST_ROOT && \
+    ./bootstrap.sh --prefix=$BOOST_ROOT && \
+    ./b2 -d1 $params && \
+    ./b2 -d0 $params install
+else
+  echo "Using cached boost at $BOOST_ROOT"
+fi
+