postgres-checkup 1.0 released

A am pleased to announce the very first release of Postgres healthcheck
automation tool, postgres-checkup.

postgres-checkup v1 collects data and generates reports in a few minutes,
allowing to reduce time of the whole healthcheck procedure from weeks to a
few hours.

- The tool can be used on Linux and MacOS machines.
- Nothing to be installed on Postgres servers ("zero install").
- Supports the collection of data using both direct Postgres connections
and using server's psql accessed via remote SSH calls.
- All checks are light and unobtrusive, tested on production databases
with 500k+ tables and 1M+ indexes.
- Some reports combine information from multiple nodes, that allows
performing complex analysis of the master and all its replicas.
- This version contains 27 reports (listed in README
<https://gitlab.com/postgres-ai-team/postgres-checkup/blob/master/README.md>),
including but not limited to:
- analysis of autovacuum and bloat estimations for tables and B-tree
indexes (section F);
- invalid, unused, and redundant indexes (section H);
- detailed query analysis based on pg_stat_statements and
pg_stat_kcache (section K).

Limitations

- no binaries for now, Go part is to be compiled;
- reports are partially automated: only "Observations" sections;
"Conclusions" and "Recommendations" are to be completed by an expert
(hence, currently, this tool aims to support work of Postgres expert
engineers; future versions will be more friendly to non-experts);
- reports in K group (Query Analysis) work only with last two snapshots;
- there is no integration with cloud APIs yet: "infrastructure" reports
are generated only for on-premise Linux setups, where ssh is available;
SQL-level reports can work with any cloud setups such as Amazon RDS, Google
Cloud SQL, Azure.

Useful Links

- About:
https://gitlab.com/postgres-ai-team/postgres-checkup/blob/master/README.md#about
- Installation and usage:
https://gitlab.com/postgres-ai-team/postgres-checkup/blob/master/README.md#installation-and-usage
- Sample report (single node only):
https://gitlab.com/postgres-ai-team/postgres-checkup-tests/blob/master/master/md_reports/1_2019_04_21T18_45_42_+0000/0_Full_report.md
- Full list of reports:
https://gitlab.com/postgres-ai-team/postgres-checkup/blob/master/README.md#the-full-list-of-checks
- Description of implemented reports:
https://gitlab.com/postgres-ai-team/postgres-checkup/blob/master/HELP.md
- Issue tracker:
https://gitlab.com/postgres-ai-team/postgres-checkup/issues
- Service desk:
incoming+postgres-ai-team-postgres-checkup-9951336-issue-(at)incoming(dot)gitlab(dot)com