use testFixtures instead of test configuration of db-core

server/sonar-ce-task-projectanalysis/build.gradle

   
   compile project(':sonar-core')
   compile project(':server:sonar-ce-task')
-  compile project(':server:sonar-db-core')
   compile project(':server:sonar-db-dao')
   compile project(':server:sonar-db-migration')
   compile project(':server:sonar-process')

server/sonar-ce/build.gradle

   compile project(':server:sonar-ce-task')
   compile project(':server:sonar-ce-task-projectanalysis')
   compile project(':server:sonar-db-dao')
-  compile project(':server:sonar-db-core')
   compile project(':server:sonar-process')
   compile project(':server:sonar-ce-task')
   compile project(':server:sonar-server-common')

server/sonar-db-core/build.gradle

   testCompile 'com.microsoft.sqlserver:mssql-jdbc'
   testCompile 'com.oracle.jdbc:ojdbc8'
   testCompile 'com.tngtech.java:junit-dataprovider'
-  testCompile 'junit:junit'
-  testCompile 'org.assertj:assertj-core'
   testCompile 'org.mockito:mockito-core'
   testCompile 'org.postgresql:postgresql'
   testCompile project(':sonar-testing-harness')
   testRuntime 'com.microsoft.sqlserver:mssql-jdbc'
   testRuntime 'com.oracle.jdbc:ojdbc8'
   testRuntime 'org.postgresql:postgresql'
+
+  testFixturesApi 'junit:junit'
+  testFixturesApi 'org.assertj:assertj-core'
+
+  testFixturesCompileOnly 'com.google.code.findbugs:jsr305'
 }
 
 test {
     systemProperty 'orchestrator.configUrl', System.getProperty('orchestrator.configUrl')
 }
 
-task testJar(type: Jar) {
-  classifier = 'tests'
-  from sourceSets.test.output
-}
-
-configurations { tests { extendsFrom testRuntime } }
-
-artifacts {
-   tests testJar
-}
-
 artifactoryPublish.skip = false
 
 // Used by core plugins
       if (release) {
         artifact sourcesJar
         artifact javadocJar
-        artifact testJar
       }
     }
   }

server/sonar-db-dao/build.gradle

   testCompile 'org.mockito:mockito-core'
   testCompile 'org.sonarsource.orchestrator:sonar-orchestrator'
   testCompile project(':sonar-testing-harness')
-  testCompile project(':server:sonar-db-core').sourceSets.test.output
+  testCompile testFixtures(project(':server:sonar-db-core'))
   testCompile project(':sonar-plugin-api-impl')
 
   testCompileOnly 'com.google.code.findbugs:jsr305'

server/sonar-db-migration/build.gradle

   testCompile 'org.mockito:mockito-core'
   testCompile project(':sonar-scanner-protocol')
   testCompile project(':sonar-testing-harness')
-  testCompile project(':server:sonar-db-core').sourceSets.test.output
+  testCompile testFixtures(project(':server:sonar-db-core'))
 
   testRuntime 'com.h2database:h2'
   testRuntime 'com.microsoft.sqlserver:mssql-jdbc'

server/sonar-db-testing/build.gradle

   // please keep the list grouped by configuration and ordered by name
 
   compile 'com.h2database:h2'
-  compile project(':server:sonar-db-core').sourceSets.test.output
+  compile testFixtures(project(':server:sonar-db-core'))
   compile project(':server:sonar-db-dao').sourceSets.test.output
 }