Minor doc fixes

docs/configuration.md

@@ -143,6 +143,7 @@ Apart from these, the following properties are also available, and may be useful
     large as the largest single object you'll serialize). Increase this if you get a "buffer limit
     exceeded" exception inside Kryo. Note that there will be one buffer <i>per core</i> on each worker.
   </td>
+</tr>
 <tr>
   <td>spark.broadcast.factory</td>
   <td>spark.broadcast. HttpBroadcastFactory</td>
@@ -175,7 +176,6 @@ Apart from these, the following properties are also available, and may be useful
 </tr>
 </table>
 
-
 # Configuring Logging
 
 Spark uses [log4j](http://logging.apache.org/log4j/) for logging. You can configure it by adding a `log4j.properties`

docs/contributing-to-spark.md

@@ -11,7 +11,10 @@ The Spark team welcomes contributions in the form of GitHub pull requests. Here
   * Maximum line length of 100 characters.
   * Always import packages using absolute paths (e.g. `scala.collection.Map` instead of `collection.Map`).
   * No "infix" syntax for methods other than operators. For example, don't write `table containsKey myKey`; replace it with `table.containsKey(myKey)`.
-- Add unit tests to your new code. We use [ScalaTest](http://www.scalatest.org/) for testing. Just add a new Suite in `core/src/test`, or methods to an existing Suite.
+- Make sure that your code passes the unit tests. You can run the tests with `sbt/sbt test` in the root directory of Spark.
+  But first, make sure that you have [configured a spark-env.sh]({{HOME_PATH}}configuration.html) with at least
+  `SCALA_HOME`, as some of the tests try to spawn subprocesses using this.
+- Add new unit tests for your code. We use [ScalaTest](http://www.scalatest.org/) for testing. Just add a new Suite in `core/src/test`, or methods to an existing Suite.
 - If you'd like to report a bug but don't have time to fix it, you can still post it to our [issues page](https://github.com/mesos/spark/issues), or email the [mailing list](http://www.spark-project.org/mailing-lists.html).
 
 # Licensing of Contributions