* [spark-2.1.x] making EventHub API call every batch (#156)
* making EventHub API call every batch
* remove unused import
* style fix
* Bug fix
* same bug fix but for DStreams
* [2.1.x] fast initialization of progress tracker (#158)
* metadata path setup and fall back to list all mechanism
* delete progress file directory after each test
* fix the failed test
* add test for metdata exist
* add test for read progress file
* revise mockito test
* update pom
* pass in all params with mockit
* change the return value of getLatestFile
* add test for checking if really queried metadata
* test: When metadata presents, we should respect it even the more recent progress file is there
* update import
* add writing logic of metadata
* update tests
* add log
* add logging
* revise logging
* add logging in commit() of structured streaming
* fix the test
* revise test for metadata not committed
* revise tests
* fix the failed test
* add partially committed progress file test
* add test of upgrade
* update upgrade test
* add test for upgrading structured streaming
* add test for no metadata
* update test name
* enabling cleanup thread
* cancel cleanup task
* add tracing
* test for fishy change
* test for fishy change
* fix the path
* code clean
* address the comments
* missed one
* metadata path setup and fall back to list all mechanism
* delete progress file directory after each test
* fix the failed test
* add test for metdata exist
* add test for read progress file
* revise mockito test
* update pom
* pass in all params with mockit
* change the return value of getLatestFile
* add test for checking if really queried metadata
* test: When metadata presents, we should respect it even the more recent progress file is there
* update import
* add writing logic of metadata
* update tests
* add log
* add logging
* revise logging
* add logging in commit() of structured streaming
* fix the test
* revise test for metadata not committed
* revise tests
* fix the failed test
* add partially committed progress file test
* add test of upgrade
* update upgrade test
* add test for upgrading structured streaming
* add test for no metadata
* update test name
* enabling cleanup thread
* cancel cleanup task
* add tracing
* test for fishy change
* test for fishy change
* fix the path
* code clean
* address the comments
* missed one
* update version for 2.1.3
* [2.1.x] should update highest offset when wake up by notify() (#153)
* should update highest offset when wake up by notify()
* fix test
* making EventHubs API call for every partition each batch