Fix RPC flaky test (#2849)

* fix rpc reconnect flaky test; remove obsolete rpcproxy log message

* rpc client proxy: replace lock with atomic variable

* rpc client proxy: removed volatile property

* RPCStabilityTests: used eventually() method to test async response

* RPCStabilityTests: remove unused import

node-api/build.gradle

@@ -49,6 +49,19 @@ dependencies {
     testCompile project(':node-driver')
 }
 
+configurations {
+        testArtifacts.extendsFrom testRuntime
+}
+
+task testJar(type: Jar) {
+    classifier "tests"
+    from sourceSets.test.output
+}
+
+artifacts {
+    testArtifacts testJar
+}
+
 jar {
     baseName 'corda-node-api'
 }