Change unit of duration params to hours to align it with duration config at other places in Loki (#998)

* Change unit of duration params to hours to align it with duration config at other places in Loki

other configurations like periodic table duration, retention are set in hours so this change makes
duration config for backup tool consistent and easy to manage configurations

* update parent docker image for bigtable backup tool

use the loki-build-image for calling circle, this is the same as what the circle job we are replacing did

add make to the alpine image used by drone to call the circle job for deployments (we use make to enumerate the image names)

Drone workspace was overwriting whole GOPATH, which made our executables go away

Moves the continuous deploy call from CircleCI to drone, because the images are
now built there.

* chore(ci/cd): breaking the circle

As the trial period for drone.io went really well (not a single failed build,
apart from merge-failures), I think it is time to make the switch to the new,
native ARM and much more performant platform.

This should fix all kinds of issues and be a solid architecture for the future
to level up our CI/CD in terms of performance and reliability.

* chore(packaging): drone.io check stage

Adds a check stage to the drone pipeline to lint and test

Simplifies tagging by removing conditionals and always publishing as `latest`
and for images also `master` on all builds (including tags).

Also fixes the tagging of the docker-driver, latest tag is back!

Possibly more links are broken?

Signed-off-by: Xiang Dai <764524258@qq.com>

Builds the loki server binary for windows as well

- restructures the docs to make them easier to explore
- rewrites promtail docs
- unifies, shortens and extends docs

use a global variable to wrap debug log statments in the pipeline to prevent unnecessary allocations when debug logging is not enabled

Signed-off-by: Xiang Dai <764524258@qq.com>

Fixes #280

- keep supporting regex for old endpoint.
- use reserved keyword for removed property in grpc

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>