Merge pull request contentstack#36 from contentstack/security

- branching and live preview support added 
- Security update and General code improvements 
- log4j removed from the dependency

Merge pull request contentstack#34 from contentstack/utility_gql

Utility gql

Merge pull request contentstack#31 from contentstack/development

Development

Merge pull request contentstack#31 from contentstack/development

Development

Merge pull request contentstack#29 from contentstack/querying_with_null

Querying with null

Merge pull request contentstack#28 from contentstack/development

Development

Merge pull request #25 from contentstack/include_fallback

Include fallback

Merge pull request contentstack#21 from contentstack/v1.5.3

## v1.5.3

Merge pull request contentstack#19 from contentstack/automation

Automation

Merge pull request contentstack#12 from contentstack/development

Development