Add Stale bot.

[Adminiuga]

Add Stale bot to clean up old issues and PRs

[codecov-commenter]

Codecov Report

Merging #987 (db6a290) into dev (21af086) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev     #987   +/-   ##
=======================================
  Coverage   82.55%   82.55%           
=======================================
  Files         189      189           
  Lines        4798     4798           
=======================================
  Hits         3961     3961           
  Misses        837      837           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 21af086...db6a290. Read the comment docs.

[coveralls]

Pull Request Test Coverage Report for Build 1102993967

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 82.555%

---

Totals
Change from base Build 1065257715:	0.0%
Covered Lines:	3961
Relevant Lines:	4798

---

💛 - Coveralls