Add weight calculations for repo scheduling in repo collection

[IsaacMilarky]

Description

• Add fields to the collection_status table to reflect estimates about a repo's general size, e. g. commit count for the facade_weight and the total pull requests plus total issues for the core_weight estimate. The pr and issue count and commit count are kept in their own column while the weight is determined from that and the age of the repo.
• Add methods to calculate a repo's facade_weight and core_weight from the repo's url and facade directory respectively.
• Add a RedisScalar class to more easily define raw scalar values with redis in a more uniform way.
• Add a time_factor to the weight calculation so that the longer a repo has been in the database without being collected the lower that repo's weight becomes.
• Note there are separate curves for determining the time_factor of repos that have already been collecting them. This separate curve increases the weight of the repo until the repo has reached 30 days since last collection and then decreases the weight from that point on.
• The time_factor for new repos is determined by the function x^4 where x is the days since repo was added
• The time_factor for old repos is determined by (x - 30)^4 for repos when x >= 30 and -(x - 30)^4 otherwise
• Adjust augur stop/kill command to get the names of all processes and store them before killing them
• Change behavior of orm insertion to collection_status table so that it automatically calculates the repo's core_weight when it is added.
• Change behavior of core collection to make collect_issues and collect_pull_requests return the number of issues and pull requests respectively. This is to save on api calls through the use of a celery chord that uses these return values to pass into core_task_update_weight_util which updates the weight for that repo.
• Add periodic task to update repo weights on midnight on even numbered days.
• Add command to augur db 'reset-repo-age' to change the repo_added field to the current timestamp. This is to make repos uniform after migrating repos from old databases to avoid repos being represented as much older than they actually are.
• Add call to 'reset-repo-age' to install script to reset the repo age whenever the instance is installed
• Remove alembic script that automatically adds the repos to collection_status without calculating weight.

Signed commits

• Yes, I signed my commits.

[ABrain7710]

Small issue

[sgoggins]

I converted the PR to a draft just to make sure I don't merge it before intended.