Add option --dry-run to check if JSON file is well-formed without modifying it.
BUMP-VERSION: 0.2.2 (was: 0.2.1)
FIX problem when current_feature was not initialized.
Issue #161: JSONFormatter: Should use a slightly different output schema.
RELATED CHANGES:

  * Add JSON schema for behave: etc/json/behave.json.schema
  * Add JSON schema validator utility script: bin/jsonschema_validate.py
  * JSON: Use JSON array mode now.
  * JSON: Added "type" to Background, Scenario, ScenerioOutline.
  * JSON: Added "error_message" to result.
  * JSON: Use now list<lines> instead of string for multi-line text
FIX typos/misspelled words in docs.
Provide self-tests for step dialects (Given/When/Then and basic steps).
Add BuildStatus info to jenisys CI (currently using cross-posting on master branches).
FIX behave.runner_util.FileLocation self-recursion in python3.
Formatter.close(): Avoid closing wrapped sys.stdout at end of test-run (fix broken detection).
RENAME: formatter.*.feature => runner.*.feature
FIX issue #162: Unnecessary ContextMaskWarnings when assert fails or exception is raised.
Verified that issues #28, #33 are fixed (related to installation on Windows).
Finalize version: 1.2.3a19
BUMP-VERSION: 1.2.3a20, for next development steps (increment).
FIX issue #164: StepRegistry.find_match() extends registered step_type lists.
NEW: StepsFormatter that provides an overview of existing step implementations.
Support lazy importing/loading (of formatters, etc.)
Improve handling for unknown formats (formatters).
Support cases w/o format option.
Use lazy imports for formatters (to speed up start-up time).