Resolve "Implement cache schema"

Summary

Implemented the schema discussed in #76 (closed). Added model classes and repositories. The overview of the schema:

MR Table

• id, 
• project_id, 
• content: {
  • author_id, 
  • state, 
  • created_at,
  • updated_at,
  • labels, 
  • approvals_before_merge
  • comments: [{assignee_id , length of comment, created_at, deleted_at }]

Issue Table

• id, 
• project_id,
• content: {
  • state,
  • assignee_id, 
  • created_at,
  • updated_at,
  • weight, 
  • time_stats : {time_estimate, total_time_spent}, 
  • comments: [{assignee_id , length of comment, created_at, deleted_at }]

Contribution Table

• id
• author_id,
• project_id,
• updated_at,
• content: {
  • # of commits, 
  • LOC: {
    • # of lines added, 
    • # of lines deleted, 
    • # of lines modified, 
    • # of lines survived}
  • epics: [epic id, # of comments made in the epic, # of issues done in that epic]}

Project_Table

• project_id,
• updated_after_issues,
• updated_before_issues,
• issues
• updated_after_mr,
• updated_before_mr,
• mrs
• updated_after_contribution,
• updated_before_contribution,
• contributions
• updated_after,
• updated_before,
• content: {
  • languages: [name of language -> percentage]
  • pipeline: {# passed, # failed, last_coverage}}

Group_Table

• group_id
• projects,
• updated_after,
• updated_before,
• members
• content:{ 
  • hours of day: [ 
  • 08-10 -> # of commits made, 
  • 10-17 -> # of commits made, 
  • 17-00 -> # of commits made, 
  • 00-08 -> # of commits made],
  • epics : [epic id -> name of epic]}

How to review

Check if the data types used make sense and match what we want, also the schema discussed in #76 (closed).

Issues and tasks closed

Closes #87 (closed)