[YUNIKORN-1697] Set max apps via namespace annotations (#117)

Additional to max and guaranteed resources allow setting max
applications on a queue via the annotations.

Closes: #117

Signed-off-by: Wilfred Spiegelenburg <wilfreds@apache.org>
diff --git a/lib/go/common/constants.go b/lib/go/common/constants.go
index afa666f..a8898ef 100644
--- a/lib/go/common/constants.go
+++ b/lib/go/common/constants.go
@@ -62,6 +62,7 @@
 	CPU                               = "vcore"
 	AppTagNamespaceResourceQuota      = "namespace.resourcequota"
 	AppTagNamespaceResourceGuaranteed = "namespace.resourceguaranteed"
+	AppTagNamespaceResourceMaxApps    = "namespace.resourcemaxapps"
 	AppTagStateAwareDisable           = "application.stateaware.disable"
 	AppTagCreateForce                 = "application.create.force"
 	NodeReadyAttribute                = "ready"
diff --git a/scheduler-interface-spec.md b/scheduler-interface-spec.md
index bb97603..bc78e25 100644
--- a/scheduler-interface-spec.md
+++ b/scheduler-interface-spec.md
@@ -771,6 +771,7 @@
 	CPU                               = "vcore"
 	AppTagNamespaceResourceQuota      = "namespace.resourcequota"
 	AppTagNamespaceResourceGuaranteed = "namespace.resourceguaranteed"
+	AppTagNamespaceResourceMaxApps    = "namespace.resourcemaxapps"
 	AppTagStateAwareDisable           = "application.stateaware.disable"
 	AppTagCreateForce                 = "application.create.force"
 	NodeReadyAttribute                = "ready"