* client/authority-discovery: Publish and query on exponential interval

When a node starts up publishing and querying might fail due to various
reasons, for example due to being not yet fully bootstrapped on the DHT.
Thus one should retry rather sooner than later. On the other hand, a
long running node is likely well connected and thus timely retries are
not needed. For this reasoning use an exponentially increasing interval
for `publish_interval`, `query_interval` and
`priority_group_set_interval` instead of a constant interval.

* client/authority-discovery/src/interval.rs: Add license header

* .maintain/gitlab: Ensure adder collator tests are run on CI

* Use diener for Polkadot companion prs

* Fix script

* Use gitlab env variable

* Update .maintain/gitlab/check_polkadot_companion_build.sh

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Initial commit

Forked at: f54614e2
Parent branch: origin/master

* Remove polkadot companion detection from branch name

Even though it was nice it was also error prone as there were no indication whatsoever on the PR
that a polkadot companion branch exists.

* Update SubstrateCli to return String

* Add default implementation for executable_name()

* Use display instead of PathBuf

* Get file_name in default impl of executable_name

* Remove String::from and use .into()

* Use default impl for executable_name()

* Use .as_str() and remove useless .to_string()

* Update only sp-io when running companion build

* Remove unneeded update of sp-io in CI

Co-authored-by: Cecile Tonglet <cecile@parity.io>

* Merge Substrate master before checking Polkadot companion

* Also merge polkadot/master into the companion pr branch

* Set email and user name

* ci: fix echo sed failure

Co-authored-by: gabriel <gabriel@parity.io>

* check_polkadot.sh: use the branch matching substrate's branch if possible

* convert to grep

* update comment

* add post-build-test stage

* check status

* fix busybox shell

* renaming for consistency

* check_polkadot: move to external script

* check_polkadot: check for companion pr

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Bastian Köcher <git@kchr.de>