Add github pull request template

Fixes: none

User interface changes?: Yes, on github only.

Code review: n/a

Testing: none, no code changes.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,18 @@
+[ 50 character, one line summary ]
+
+[ Description of the changes in this commit. It should be enough
+  information for someone not following this development to understand. 
+  Lines should be wrapped at about 72 characters. ]
+
+Fixes: [NGT-ED Github issue #]
+
+User interface changes?: [Yes (describe what changes), No]
+
+Code review: [Names]
+
+Test suite: [suite name, machine, compilers]
+Test baseline: [changeset id]
+Test namelist changes:
+Test answer changes: [bit for bit, roundoff, climate changing]
+
+Test summary: [Remove 'PASS' fields]