Merge pull request #32 from jameinel/3.6-gofmt

chore: just 'go fmt' all the files

Merge pull request #25 from tlm/fix-firewall-issues-macos

Fixes firewall issues on macos.

Merge pull request #24 from hpidcock/fix-read-concern

#24

For safety, we need to set the readConcern and writeConcern in transactions and ensure readPreference is on the primary.

Merge branch 'v2'

Fix testing package.

Merge pull request #23 from hpidcock/v3-testing

Merge branch 'v2-testing' into v3-testing

Merge pull request #20 from hpidcock/master

#20

This PR:\r
- Bumps to github.com/juju/mgo/v3\r
- Fixes all the unit tests (skips a few that don't work in mongo 4.4 or features we don't use i.e. MapReduce)\r
- Improve sstxn retrying on retry-able errors (added error code handling here, will update juju/txn library which has the actual retry logic)\r
- sstxn txn log writes need the same error handling as any other write op.\r
- Improve CommitTransaction and AbortTransaction by bringing across the double-tap from Mongo Driver\r
- Simplify possible Query errors returned to callers by converting net.OpError to io.EOF, this improves test stability too.\r
- Non primary write errors force a cluster sync and discard the primary socket for that session. If there is a current transaction, abort it.

Merge pull request #22 from hpidcock/v2-testing

Bring mgo juju/testing into mgo module.

Merge pull request #21 from juju/master

Merge current "v2" master into "v2"