Druid select queries don't allow setting of a timezone. This commit
will parse the timestamps coming out of Druid and reformat them using
the user's report timezone or system timezone. This allows Druid
select queries to have similar timezone semantics to other supported
databases.

Fixes #3690

This utility function temporarily changes the JVM's timezone to
something different and puts it back after the body of the form is
invoked. Moving it to metabase.test.util so other tests can use it.

Switch from the PostgreSQL driver to Redshift [ci drivers]

Fix word mistakes in docs.

Pull Release 0.26.1 back in

Redshift JDBC connection URLs can be writtend with the postgresql
subprotocol or the redshift protocol. This can cause problems as the
DriverManager (depending on how the classes have been loaded) will be
the first matching driver for a subprotocol. We could get the Redshift
driver when we were intending to get the PostgreSQL driver. Adding
this flag will ensure that we don't inadvertantly get the Redshift
driver when we intended to get PostgreSQL driver.

Calling metabase.test.data/id with no args ensured the db was created,
I added that same check to the other arities of the id method.

Fixes #5424

Fix performance problems where xray visualizations were rerendered unnecessarily

Reverse the order of dropping the async xray tables

On MySQL dropping the computation_job table first violates the FK
constraints. This commit just flips the order of deletes. It also adds
a new validCheckSum to ensure users that ran the previous version fo
the migration will still work.

Fixes #6050

* add preview banner

* add icon / survey link

Try to fix transient CI failures in ObjectDetail.integ.spec.js

Create migration to will safely revert the async xray tables [ci all]

The `computation_job` and `computation_job_result tables` accidentally
made it into 0.26.0.RC2. This commit will remove those tables as a
separate migration if they are present.

Don't show retired metrics in query builder action widget

Change logging level to INFO

Previously we were using the PostgreSQL driver for connecting to
Redshift. Newer versions of PostgreSQL require newer drivers that are
no longer compatible with Redshift which has prevented us from
upgrading. By switching to the AWS Redshift driver, we can upgrade the
PostgreSQL driver independently.

Fix a top level data/id call

There's a def of a data structure that contains a data/id call. This
can be a problem if the database hasn't been initialized yet. This
commit wraps it in a thunk to ensure it happens when the test run, not
when the code is compiled.

Fix the issue with flashing 'Custom' option in new question flow

This commit changes the default logging level from DEBUG to INFO for
all of the metabase logging categories. Logging often includes
pretty-printing strings which can be costly from a performance
perspective. Users wanting more verbose logging and override these
settings with the -Dlog4j.configuration parameter.

Fix Beanstalk instructions

Pull docs commits into master