[HUDI-121] Fix licensing issues found during RC voting by general incubator group

DISCLAIMER-WIP

@@ -0,0 +1,26 @@
+Apache Hudi (incubating) is an effort undergoing incubation 
+at The Apache Software Foundation (ASF), sponsored by the Apache Incubator. 
+
+Incubation is required of all newly accepted projects until a further review 
+indicates that the infrastructure, communications, and decision making process 
+have stabilized in a manner consistent with other successful ASF projects.
+
+While incubation status is not necessarily a reflection of the
+completeness or stability of the code, it does indicate that the
+project has yet to be fully endorsed by the ASF.
+
+Some of the incubating project's releases may not be fully compliant
+with ASF policy. For example, releases may have incomplete or
+un-reviewed licensing conditions. What follows is a list of known
+issues the project is currently aware of (note that this list, by
+definition, is likely to be incomplete): 
+
+ * The LICENSE and NOTICE files may not be complete and will be fixed with the next release.
+
+If you are planning to incorporate this work into your
+product or project, please be aware that you will need to conduct a
+thorough licensing review to determine the overall implications of
+including this work. For the current status of this project through the Apache
+Incubator visit: 
+
+http://incubator.apache.org/projects/hudi.html