Update checkPRs to count 2 commits as valid

[southekal]

Background:

• devICT's 2019 hacktoberfest requires 2 qualifying commits to be eligible for a set of stickers (requirement is different from the previous year where 4 commits were needed).

Issue:

• the checkPRs js method! is looking for 4 valid commits instead of 2.

Fix:

• update the javascript to count 2 commits as valid instead of 4

[M-ZubairAhmed]

Please take a look at https://github.com/devict/hacktoberfest/pull/61