Fix deployment of spark_python_operator (#1033)

This properly packages the spark operation "kernelspec"
and adds spark_python_operator to the corresponding list
of exposed kernelspecs in the k8s deployment scripts.

The operator-related scripts/templates have been moved to
kernel-launchers/operators to more easily enable deployment 
and not clutter other Kubernetes kernelspecs with unrelated 
scripts/templates.

etc/Makefile

@@ -52,9 +52,10 @@ TOREE_LAUNCHER_FILES:=$(shell find kernel-launchers/scala/toree-launcher/src -ty
 	@echo ../build/kernelspecs/spark_python_{conductor*,yarn*} | xargs -t -n 1 cp -r kernel-launchers/python/scripts
 	@echo ../build/kernelspecs/spark_R_{conductor*,yarn*} | xargs -t -n 1 cp -r kernel-launchers/R/scripts
 	@echo ../build/kernelspecs/spark_scala_{conductor*,yarn*} | xargs -t -n 1 cp -r kernel-launchers/scala/lib
-	# Container-based kernelspecs just get the container launchers
+	# Container-based kernelspecs (and operators) just get the container launchers
 	@echo ../build/kernelspecs/{python,R,scala,python_tf,python_tf_gpu}_kubernetes | xargs -t -n 1 cp -r kernel-launchers/kubernetes/*
 	@echo ../build/kernelspecs/{python,R,scala,python_tf,python_tf_gpu}_docker | xargs -t -n 1 cp -r kernel-launchers/docker/*
+	@echo ../build/kernelspecs/spark_python_operator | xargs -t -n 1 cp -r kernel-launchers/operators/*
         # Populate kernel resources.  Because tensorflow is also python, it should be last.
 	@echo ../build/kernelspecs/*R* | xargs -t -n 1 cp -r kernel-resources/ir/*
 	@echo ../build/kernelspecs/*scala* | xargs -t -n 1 cp -r kernel-resources/apache_toree/*

etc/kubernetes/enterprise-gateway.yaml

@@ -184,7 +184,7 @@ spec:
           value: "60"
 
         - name: EG_KERNEL_WHITELIST
-          value: "'r_kubernetes','python_kubernetes','python_tf_kubernetes','python_tf_gpu_kubernetes','scala_kubernetes','spark_r_kubernetes','spark_python_kubernetes','spark_scala_kubernetes'"
+          value: "'r_kubernetes','python_kubernetes','python_tf_kubernetes','python_tf_gpu_kubernetes','scala_kubernetes','spark_r_kubernetes','spark_python_kubernetes','spark_scala_kubernetes','spark_python_operator'"
 
         - name: EG_DEFAULT_KERNEL_NAME
           value: "python_kubernetes"

etc/kubernetes/helm/enterprise-gateway/values.yaml

@@ -36,6 +36,7 @@ kernel:
     - spark_r_kubernetes
     - spark_python_kubernetes
     - spark_scala_kubernetes
+    - spark_python_operator
   # Default kernel name should be something from the whitelist
   defaultKernelName: python_kubernetes