Release v1.4.0 for PG11

Release Notes for Apache AGE release v1.4.0 for PG 11

Apache AGE 1.4.0 - Release Notes

NOTE: Some of these reference the master branch PR that was
either applied to lower versions via a separate PR or
merged into a newly created branch.

Added license in Python driver README.md (#956)
Added the toStringList() function (#1128)
Added toBooleanList() (#1165)
Added toFloatList() function (#1016)
Added toIntegerList() function (#1025)
Added regression tests for MATCH clause using labels only (#1019)
Added REGTYPEOID to toString function (#1036)
Added Dockerfile.dev & move docker-related files to "docker/" (#943)
Fixed complex MERGE causes crash (#897) (#961)
Fixed docker build files (#1104)
Fixed case sensitivity on label usage of reserved keyword (#1040)
Fixed issue 1000: Indexes created on WHERE (#1133)
Fixed issue 1002: Invalid reuse of variables in MATCH clause (#1003)
Fixed issue 1033: access operator on vle edge lists (#1037)
Fixed issue 1043: ERROR: container must be an array or object (#1046)
Fixed issue 1124: Segmentation fault when using specific tables (#1125)
Fixed issue 395: ERROR: container is not an agtype array (#1039)
Fixed issue 870: regarding orderability and added regression tests (#994)
Fixed issue 876: column reference "_age_default_alias_0" is ambiguous (#931)
Fixed issue 975: Invalid reuse of variables in CREATE clause (#977)
Fixed issue 989: Impossible to create array with > 100 items (#1001)
Fixed memory leak issues with age_load (#1142)
Fixed memory leaks in MERGE (merge_edge & merge_vertex) (#958)
Fixed MERGE crashes due to incorrect label type (#957)
Fixed MERGE variable reuse (#997)
Fixed misspellings in many AGE files (#985)
Fixed warning messages in DockerHub builds. (#1075)
Modified test_agtypes to view useful testing message (#992)
Optimised Antlr4ResultHandler initialization (#1169)
Updated CIs to pull correct image based on branch (#1105)
Updated files, format, and version information (#1063)
Updated README.