The memory leak job pulls TSDB dev tools from bitbucket but only two
files from that repository are needed.
This commit copy the files from the `tsdb-dev-tools` repository, remove
the need to clone the repository, update the memory leak job to use
these files, and remove the two secrets containing the environment
variables `USR` and `PASSWORD`.
Using the new flag available in Docker images, turn off telemetry in Timescale-built Docker images used by Travis. We do not pass the flag to Postgres Docker images.
Out of order, random inserts into TimescaleDB in the past
sometimes caused continuously increasing memory usage.
These checks are being added to ensure that there are no
memory spike regressions via a cron Travis job.
