Paid feature docs

Add context to the IOException when creating temp files

When sending an email with an attachment, we write the attachment as a
temp file. This uses the `java.io.File/createTempFile` method. If for
some reason we're not able to write that file, maybe because we don't
have sufficient permissions, that method will throw an
IOException. The IOException doesn't include the path of the file it
was trying to create, which makes it difficult to diagnose and
fix. This commit catches that original IOException and rethrows it
with the path of the temp directory that is being used.

Fixes #8405

Fix GA segments; allow cache-ttl and native.collection keys in query

Query Processor Store [ci drivers]

Add deploy webhook back to CircleCI 2.0 config

Upgrade node version in packages.json and the Dockerfile [ci all]

Using version 220 of `jest-localstorage-mock` required that we upgrade
our version of NodeJS from our previous minimum of 6.11.3. To support
that, this commit switches from the deprecated
`java:openjdk-8-jdk-alpine` docker image to the newer
`openjdk:8-jdk-alpine` image. This image is running Alpine version 3.8 which
has NodeJS 8.11.4 in it's repository. This also bumps the minimum
version of node in the packages.json file.

Query schema fixes; add query validation middleware [ci drivers]

Add a unique index to databasechangelog

Previously there was nothing to uniquely identify a row in the
databasechangelog table as the uniqueness constraint was removed by
Liquibase (see https://liquibase.jira.com/browse/CORE-1909). Not
having something to uniquely identify a row can cause issues for
database replication software. Since we only support PostgreSQL, MySQL
and H2, the composite key referenced in the above issue (ID, AUTHOR,
FILENAME) will work for us. This commit puts that uniqueness
constraint back in for users wanting to replicate the Metabase
application database.

Fixes #8266

Query normalization

Merge release-0.30.2 back into master

Gauge visualization