Support for Buffers

[chopper]

gulp-aws currently claims it only supports streams (index.js, lines 34-38):

        // Only streams supported
        if (file.isBuffer()) {
            this.emit('error', new PluginError(PLUGIN_NAME, new Error('Only streams supported'), { showStack: true }));
            return done();
        }

However none of the functionality seems to be particular to streams. In fact, after commenting out the above lines, the plugin works fine with buffered streams. I suggest removing the above check.