Catch up Embulk 0.10

[enhancement] Remove deprecated functions #76

Catch up Embulk 0.10

[enhancement] catch up Embulk 0.10 #73

v0.2.12

• [enhancement] Fix performance issue #47

v.0.2.10

• [enhancement] Add Zendesk market place header #44

v0.2.9

• [fixed] start_time is not merged to query, causing infinite loop #42

v0.2.8

• [fixed] Raise DataError instead of TempError after giving up for TempError #40
• [enhancement] Only rescue TempError when executing thread pool, only create/shutdown pool once during retry, move retry to inside of execute_thread_pool

v0.2.7

• [fixed] Ensure thread pool is shutdown #38
• [enhancement] Add retry for temporary error: missing required key from JSON response

v0.2.6

• [enhancement] Enable incremental loading for ticket_metrics

v0.2.5

• [enhancement] Replace thread gem with concurrent-ruby, it's more robust and has better queue management #33

v0.2.4

• [fixed] Fix thread pool bottleneck #31