HUDI-123 Rename code packages/constants to org.apache.hudi (#830)

- Rename com.uber.hoodie to org.apache.hudi
- Flag to pass com.uber.hoodie Input formats for hoodie-sync
- Works with HUDI demo. 
- Also tested for backwards compatibility with datasets built by com.uber.hoodie packages
- Migration guide : https://cwiki.apache.org/confluence/display/HUDI/Migration+Guide+From+com.uber.hoodie+to+org.apache.hudi

hudi-utilities/src/test/resources/delta-streamer-config/target.avsc

@@ -0,0 +1,37 @@
+{
+  "type" : "record",
+  "name" : "triprec",
+  "fields" : [
+  {
+    "name" : "timestamp",
+    "type" : "double"
+  }, {
+    "name" : "_row_key",
+    "type" : "string"
+  }, {
+    "name" : "rider",
+    "type" : "string"
+  }, {
+    "name" : "driver",
+    "type" : "string"
+  }, {
+    "name" : "begin_lat",
+    "type" : "double"
+  }, {
+    "name" : "begin_lon",
+    "type" : "double"
+  }, {
+    "name" : "end_lat",
+    "type" : "double"
+  }, {
+    "name" : "end_lon",
+    "type" : "double"
+  }, {
+    "name" : "fare",
+    "type" : "double"
+  }, {
+    "name" : "haversine_distance",
+    "type" : "double"
+  }]
+}
+