[ci skip]updated documentation: added sass and less extensions
Merge pull request #12921 from kuldeepaggarwal/documentation-updation

[ci skip]updated documentation: added sass and less extensions
Drop unused param `should_be_quoted` to `PostgreSQLColumn#array_to_string`
Merge pull request #12928 from vipulnsward/drop_unused_param

Drop unused param `should_be_quoted` to `PostgreSQLColumn#array_to_string`
Properly require database tasks so we have access to the raised constant

Fix travis failures.
Add description for db:create and db:drop test tasks in AR

This will help identify these tasks exists, since they are easier to
setup things for running all AR tests.
Address test_merging_where_relations failure by adding `order("posts.id")`
Merge pull request #12929 from yahonda/test_merging_where_relations_add_order

Address test_merging_where_relations failure by adding order
Do not count query for all_constraints and all_tab_cols in Oracle
Merge pull request #12931 from yahonda/add_oracle_ignored

Do not count query for all_constraints and all_tab_cols tested with Oracle