Added Apache notice to TStudentKernel

Author: mandar2812

src/main/scala/io/github/mandar2812/dynaml/kernels/TStudentKernel.scala

@@ -1,3 +1,21 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+* */
 package io.github.mandar2812.dynaml.kernels
 
 import breeze.linalg.{norm, DenseVector, DenseMatrix}