Adding hoodie-spark to support Spark Datasource for Hoodie

- Write with COW/MOR paths work fully
 - Read with RO view works on both storages*
 - Incremental view supported on COW
 - Refactored out HoodieReadClient methods, to just contain key based access
 - HoodieDataSourceHelpers class can be now used to construct inputs to datasource
 - Tests in hoodie-client using new helpers and mechanisms
 - Basic tests around save modes & insert/upserts (more to follow)
 - Bumped up scala to 2.11, since 2.10 is deprecated & complains with scalatest
 - Updated documentation to describe usage
 - New sample app written using the DataSource API

hoodie-spark/src/test/java/DataSourceTestUtils.java

@@ -0,0 +1,50 @@
+/*
+ *  Copyright (c) 2017 Uber Technologies, Inc. (hoodie-dev-group@uber.com)
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *           http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *
+ */
+
+import com.uber.hoodie.common.TestRawTripPayload;
+import com.uber.hoodie.common.model.HoodieRecord;
+
+import org.apache.spark.api.java.JavaRDD;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+/**
+ * Test utils for data source tests.
+ */
+public class DataSourceTestUtils {
+
+    public static Optional<String> convertToString(HoodieRecord record) {
+        try {
+            String str = ((TestRawTripPayload) record.getData()).getJsonData();
+            str = "{" + str.substring(str.indexOf("\"timestamp\":"));
+            return Optional.of(str.replaceAll("}", ", \"partition\": \"" + record.getPartitionPath() + "\"}"));
+        } catch (IOException e) {
+            return Optional.empty();
+        }
+    }
+
+    public static List<String> convertToStringList(List<HoodieRecord> records) {
+        return records.stream().map(hr -> convertToString(hr))
+                .filter(os -> os.isPresent())
+                .map(os -> os.get())
+                .collect(Collectors.toList());
+    }
+}