(LTH-115) Fix Boost.Log sink initialization with Boost 1.62

In Boost 1.62, the way sink argument forwarding appears to have changed

in such a way that it failed to identify the implicit creation of a

color_writer. Switch to explicitly creating the color_writer sink.

https://github.com/puppetlabs/leatherman/commit/e8196d55ecac7f2bf3aa5cb0aefef0122e63db21

--- vendor/leatherman/logging/src/logging.cc.orig	2015-11-25 00:14:00 UTC

+++ vendor/leatherman/logging/src/logging.cc

@@ -72,7 +72,7 @@ namespace leatherman { namespace logging

         core->remove_all_sinks();

         using sink_t = sinks::synchronous_sink<color_writer>;

-        boost::shared_ptr<sink_t> sink(new sink_t(&dst));

+        boost::shared_ptr<sink_t> sink = boost::make_shared<sink_t>(boost::make_shared<color_writer>(&dst));

         core->add_sink(sink);

 #if (!defined(__sun) && !defined(_AIX)) || !defined(__GNUC__)