Trying to create cast_type lookup for base adapter
Disable serialized_attributes test for AR > 4.2

- https://github.com/rails/rails/pull/15704/ has deprecated
  serialized_attributes.
- It will be removed in Rails 5.
Pass serialization tests on AR 4.2

- Made testing of seriliazed_attributes with init_with only with AR less
  than 4.2 as 4.2 has added more stricter code to check the
  serialization mismatch when the object gets initialized.
- Made testing of raising exception while saving object with
  serialization mismatch only with AR less than 4.2.
- Added test case for testing raising exception while initializing new
  object with serialization mismatch when AR version is greater than or
  equal to 4.2.
Update schema_dump test with scale 0

- Rails 4.2 has changed the way decimals with scale 0 are treated.
- Commit - https://github.com/rails/rails/commit/6b2ff4fa
- They are now treated as integers without scale.
- So scale: 0 is not in the output of schema_dump any more.
Skipped serialization tests related to custom and bcrypt code for AR > 4.2

- These 2 tests were changed on Rails side in
  https://github.com/rails/rails/commit/24b6fa59523dc9eccf0a7c553d3da083ea860045
- The behavior is changed and they are not passing on Rails side also.
  So skipped them for AR > 4.2
Added the updated test case for serialized with coder for Rails 4.2

- The test was introduced in Rails in this commit https://github.com/rails/rails/commit/24b6fa59523dc9eccf0a7c553d3da083ea860045
Updated rails42 with Rails 4.2.0.beta2
Rails added null: false constraint on timestamps columns

- Commit - https://github.com/sgrif/rails/commit/ea3ba34506c72d636096245016b5ef9cfe27c566
- This right now gives deprecation warning that in Rails 5.0, null: true
  will be changed to null: false by default.
- Updated our models to be null: false.
Update serialization tests so that they are tested for correct AR version
Fix test related to default negative values for 4.2

- Rails no longer type casts default value at the time of column
  initialization
  https://github.com/rails/rails/commit/4d3e88fc757a1b6f6c468418af01dca677e41edf.
- Also the default attribute of Column instance is not public. The
  public API is column_defaults method.
- Updated test to use this method for AR > 4 and fallback to default for
  older versions.
 Fixed issue related to clearing SQLCounter log

- Added clear_log method present in ActiveRecord to test_helper.
- This method can be used to clear the log of queries.
- Fixed logic of setting log to the currently executed queries.
- Updated list of ignored queries by changing regex for PRAGMA queries.
- Made it PRAGMA same as ActiveRecord.
Fix failure related to string primary key

- Now Rails adds default limit of the columns in the schema dump.
- https://github.com/rails/rails/commit/2c76793f087e212ff4c6d835656a9a95c8bfeaa5
- Updated schema_dumper test for AR > 4.2
Use correct Regex for 4.0 and 4.1 non-primary key test
Definition of case_sensitive_modifier is changed in Rails 4.2

- We are passing table_attribute now so that Arel can calculate quoted
  node based on that.
- Commit - https://github.com/rails/rails/commit/a38e957f8021bbd9a2fa2fc9f5bcea9d9ba6e7ef
Update postgres adapter column definition with cast_type
In Rails 4.2, support for Jsonb datatype was added for postgres

Commit - https://github.com/rails/rails/commit/99b82fdf03fcf6d6ca8e2d810ba35011723a5267
Add support for XML as present in Rails 4.2 for PG

- This was done to not rely on sql_type for quoting xml values.
Commit - https://github.com/rails/rails/commit/f6968bd601e38fb5060c7bc577331f97ed5e232c
Type is changed from Rails 4.2
Preserve type when dumping bit and bit varying columns

Commits -
  https://github.com/rails/rails/commit/fcd5e56b862ffea9a8c1cea0c622472c5346474b
  https://github.com/rails/rails/commit/d5411fb37ca9a35f49a55fd52d2aefb7956b3e41
use AR42_COMPAT constant for AR 4.2