clean-up trailing whitespace (#453)

These changes have been mostly auto-generated with:

	find . -type f -print0 | xargs -0 perl -pi -e 's/ +$//'

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

exercises/mri/s1-runtime.json

@@ -33,7 +33,7 @@
         "port": 1
       }
     },
- 
+
     {
       "table": "MyIngress.ipv4_lpm",
       "match": {