Update Vagrantfiles for dogwood.3

vagrant/release/analyticstack/Vagrantfile

@@ -73,6 +73,9 @@ openedx_releases = {
   "named-release/dogwood.2" => {
     :name => "analyticstack", :file => "dogwood-analyticstack-2016-03-15.box",
   },
+  "named-release/dogwood.3" => {
+    :name => "analyticstack", :file => "dogwood-analyticstack-2016-03-15.box",
+  },
   "named-release/dogwood" => {
     :name => "analyticstack", :file => "dogwood-analyticstack-2016-03-15.box",
   },

vagrant/release/devstack/Vagrantfile

@@ -71,6 +71,9 @@ openedx_releases = {
   "named-release/dogwood.2" => {
     :name => "dogwood-devstack-2016-03-09", :file => "dogwood-devstack-2016-03-09.box",
   },
+  "named-release/dogwood.3" => {
+    :name => "dogwood-devstack-2016-03-09", :file => "dogwood-devstack-2016-03-09.box",
+  },
   "named-release/dogwood" => {
     :name => "dogwood-devstack-rc2", :file => "20151221-dogwood-devstack-rc2.box",
   },

vagrant/release/fullstack/Vagrantfile

@@ -20,6 +20,9 @@ openedx_releases = {
   "named-release/dogwood.2" => {
     :name => "dogwood-fullstack-rc2", :file => "20151221-dogwood-fullstack-rc2.box",
   },
+  "named-release/dogwood.3" => {
+    :name => "dogwood-fullstack-rc2", :file => "20151221-dogwood-fullstack-rc2.box",
+  },
   "named-release/dogwood.rc" => {
     :name => "dogwood-fullstack-rc2", :file => "20151221-dogwood-fullstack-rc2.box",
   },