updating azure-keyvault preview package version in install doc
@@ -68,7 +68,7 @@ Preview packages
===================================== =========
Package name Version
===================================== =========
-azure-keyvault 0.3.3
+azure-keyvault 0.3.4
azure-monitor 0.3.0
azure-mgmt-resource 1.1.0rc1
azure-mgmt-compute 1.0.0rc1
