Update Issue and PR Templates (#1462)

* update issue template

* update pr template

.github/ISSUE_TEMPLATE.md

@@ -11,7 +11,15 @@ Immediate support:
 
 <!--
 If feature: A description of the feature
-If bug: Steps to reproduce + link to sample repo
+If bug: Steps to reproduce
+-->
+
+# Link to reproduction sandbox
+
+<!--
+Link to an app sandbox for reproduction
+
+Note: Failure to provide a sandbox application for reproduction purposes will result in the issue being closed.
 -->
 
 # Expected result

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,17 +6,18 @@
 <!--
 Please use the following link syntaxes:
 
-- #49 (to reference issues in the current repository)
-- strongloop/loopback#49 (to reference issues in another repository)
+- connect to #49 (to reference issues in the current repository)
+- connect to strongloop/loopback#49 (to reference issues in another repository)
 -->
 
-- None
+- connect to <link_to_referenced_issue>
 
 ### Checklist
 
 <!--
-Please mark your choice with an "x" (i.e. [x], see
+- Please mark your choice with an "x" (i.e. [x], see
 https://github.com/blog/1375-task-lists-in-gfm-issues-pulls-comments)
+- PR's without test coverage will be closed.
 -->
 
 - [ ] New tests added or existing tests modified to cover all changes