Use prepared statements in ExecutorDao#recoverWorkflowInstancesFromDeadNodes and updateActiveTimestamp
improve logging
Update spring 4.0.6->4.1.0, deploy 2.8.1->2.8.2, install 2.5.1->2.5.2
Merge pull request #27 from NitorCreations/improve-logging

Improve logging: Writes exception class names when logging.
Add nflow logo
Update README.md
Update README.md
Make logo smaller
Add externalId to ListWorkflowInstanceResponse
Added test for executor recovery
Merge pull request #26 from NitorCreations/executor-dao-prepared-statement

Use prepared statements in ExecutorDao
Merge pull request #28 from NitorCreations/external-id-in-list-workflows

Add externalId to ListWorkflowInstanceResponse
Merge pull request #29 from NitorCreations/executor-recovery-test-new

Added test for executor recovery
Add executor_group to nflow_workflow_uniq index
Change nflow_workflow.external_id to not null in database
Querying fetches only within current executorGroup
Change nflow_workflow.executor_group to not null in database
Use binary backoff for errors by default. Add builder for WorkflowSettings.
Merge pull request #30 from NitorCreations/executor-group-unique

Better isolation between executor groups
Merge pull request #31 from NitorCreations/exponential-retry-delay

Use binary backoff for errors by default. Add builder for WorkflowSettin...