Release v0.7.56

What's Changed

• Array filtering support (Part #1): API and Mongo filter refactoring by @suresh-prakash in #173
• Array filtering support (Part #2): MongoDB implementation and integration test setup by @suresh-prakash in #188
• Array filtering support (Part #3): Postgres relational filter refactoring by @suresh-prakash in #189
• Array filtering support (Part #4): Postgres array filter impl. by @suresh-prakash in #191
• Introduce NOT logical operator and add tests by @suresh-prakash in #192

Full Changelog: v0.7.55...v0.7.56