HOTFIX: Clean up build in network module.

This is currently breaking the package build for some people (including me).

This patch does some general clean-up which also fixes the current issue.
- Uses consistent artifact naming
- Adds sbt support for this module
- Changes tests to use scalatest (fixes the original issue[1])

One thing to note, it turns out that scalatest when invoked in the
Maven build doesn't succesfully detect JUnit Java tests. This is
a long standing issue, I noticed it applies to all of our current
test suites as well. I've created SPARK-4159 to fix this.

[1] The original issue is that we need to allocate extra memory
for the tests, happens by default in our scalatest configuration.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #3025 from pwendell/hotfix and squashes the following commits:

faa9053 [Patrick Wendell] HOTFIX: Clean up build in network module.

1 files changed, 1 insertions, 1 deletions

diff --git a/core/pom.xml b/core/pom.xml
index 8020a2daf8..6963ce4777 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -46,7 +46,7 @@
     </dependency>
     <dependency>
       <groupId>org.apache.spark</groupId>
-      <artifactId>network</artifactId>
+      <artifactId>spark-network-common_2.10</artifactId>
       <version>${project.version}</version>
     </dependency>
     <dependency>