Added license information to all source files

Author: prat-man

src/main/java/tk/pratanumandal/unique4j/Unique4jException.java

@@ -1,3 +1,20 @@
+/**
+ * Copyright 2019 Pratanu Mandal
+ *
+ * Licensed 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 tk.pratanumandal.unique4j;
 
 /**

src/test/java/tk/pratanumandal/unique4j/Unique4jTest.java

@@ -1,3 +1,20 @@
+/**
+ * Copyright 2019 Pratanu Mandal
+ *
+ * Licensed 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 tk.pratanumandal.unique4j;
 
 import org.junit.Test;