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.

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>

network/common/pom.xml

@@ -27,12 +27,12 @@
   </parent>
 
   <groupId>org.apache.spark</groupId>
-  <artifactId>network</artifactId>
+  <artifactId>spark-network-common_2.10</artifactId>
   <packaging>jar</packaging>
-  <name>Shuffle Streaming Service</name>
+  <name>Spark Project Common Network Code</name>
   <url>http://spark.apache.org/</url>
   <properties>
-    <sbt.project.name>network</sbt.project.name>
+    <sbt.project.name>network-common</sbt.project.name>
   </properties>
 
   <dependencies>
@@ -59,6 +59,11 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.novocode</groupId>
+      <artifactId>junit-interface</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>log4j</groupId>
       <artifactId>log4j</artifactId>
@@ -69,25 +74,20 @@
       <artifactId>mockito-all</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.scalatest</groupId>
+      <artifactId>scalatest_${scala.binary.version}</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
-
   <build>
-    <outputDirectory>target/java/classes</outputDirectory>
-    <testOutputDirectory>target/java/test-classes</testOutputDirectory>
+    <outputDirectory>target/scala-${scala.binary.version}/classes</outputDirectory>
+    <testOutputDirectory>target/scala-${scala.binary.version}/test-classes</testOutputDirectory>
     <plugins>
       <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <version>2.17</version>
-        <configuration>
-          <skipTests>false</skipTests>
-          <includes>
-            <include>**/Test*.java</include>
-            <include>**/*Test.java</include>
-            <include>**/*Suite.java</include>
-          </includes>
-        </configuration>
+        <groupId>org.scalatest</groupId>
+        <artifactId>scalatest-maven-plugin</artifactId>
       </plugin>
     </plugins>
   </build>

project/SparkBuild.scala

@@ -31,10 +31,10 @@ object BuildCommons {
   private val buildLocation = file(".").getAbsoluteFile.getParentFile
 
   val allProjects@Seq(bagel, catalyst, core, graphx, hive, hiveThriftServer, mllib, repl,
-  sql, streaming, streamingFlumeSink, streamingFlume, streamingKafka, streamingMqtt,
+  sql, networkCommon, streaming, streamingFlumeSink, streamingFlume, streamingKafka, streamingMqtt,
   streamingTwitter, streamingZeromq) =
     Seq("bagel", "catalyst", "core", "graphx", "hive", "hive-thriftserver", "mllib", "repl",
-      "sql", "streaming", "streaming-flume-sink", "streaming-flume", "streaming-kafka",
+      "sql", "network-common", "streaming", "streaming-flume-sink", "streaming-flume", "streaming-kafka",
       "streaming-mqtt", "streaming-twitter", "streaming-zeromq").map(ProjectRef(buildLocation, _))
 
   val optionallyEnabledProjects@Seq(yarn, yarnStable, yarnAlpha, java8Tests, sparkGangliaLgpl, sparkKinesisAsl) =
@@ -142,7 +142,9 @@ object SparkBuild extends PomBuild {
 
   // TODO: Add Sql to mima checks
   allProjects.filterNot(x => Seq(spark, sql, hive, hiveThriftServer, catalyst, repl,
-    streamingFlumeSink).contains(x)).foreach(x => enable(MimaBuild.mimaSettings(sparkHome, x))(x))
+    streamingFlumeSink, networkCommon).contains(x)).foreach {
+      x => enable(MimaBuild.mimaSettings(sparkHome, x))(x)
+    }
 
   /* Enable Assembly for all assembly projects */
   assemblyProjects.foreach(enable(Assembly.settings))