Update README.md

Author: benmccann

README.md

@@ -20,7 +20,7 @@ Note that you must be using MongoDB replica sets since this river tails the oplo
 
 | MongoDB River Plugin | ElasticSearch | MongoDB | TokuMX |
 |--------------------------|------------------|---------------|---------------|
-| master | 1.4.2 | 3.0.0 | 1.5.1 |
+| master | 1.7.3 | 3.0.0 | 1.5.1 |
 | 2.0.9 | 1.4.2 | 3.0.0 | 1.5.1 |
 | 2.0.5 | 1.4.2 | 2.6.6 | 1.5.1 |
 | 2.0.2 | 1.3.5 | 2.6.5 | 1.5.1 |