Add build instruction in readme

For someone who first try to build this project, it might fail when run
"mvn clean install" and remind "non-resolvable parent". So at this
point, try to run "mvn clean install" in the "oparent" project can solve
this issue.

Signed-off-by: qingshuting <qingshuting1@huawei.com>
Change-Id: If99480f9e2d16c9480b4ffd8aae88bbf0e98cdc6
Issue-ID: POLICY-4167

diff --git a/README.md b/README.md
index d8c91eb..45fc0ba 100644 (file)
--- a/README.md
+++ b/README.md
@@ -6,3 +6,6 @@ This source repository contains the ONAP Policy Parent repository that contains
 overarching build pom.xml to build ALL the repos under policy/*
 
 To build it using Maven 3, run: mvn clean install
+
+Reminder:
+If maven reports "non-resolvable parent POM", run "mvn clean install" on project "oparent" first.
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