Added suggest section to composer.json w/ DV components (#216)

Fixes #210

Author: JeroenDeDauw

composer.json

@@ -38,6 +38,11 @@
 		"data-values/time": "~0.2",
 		"phpunit/phpunit": "~4.8"
 	},
+	"suggest": {
+		"data-values/geo": "Needed for deserialization of geographical values",
+		"data-values/number": "Needed for deserialization of numerical values",
+		"data-values/time": "Needed for deserialization of time values"
+	},
 	"autoload": {
 		"psr-4": {
 			"Wikibase\\DataModel\\": "src/"