add tests condition

Author: AvicennaJr

README.md

@@ -360,6 +360,8 @@ There are documentations for two languages, English and Kiswahili, which are bot
 
 Clone the repo, hack it, make sure all tests are passing then submit a pull request.
 
+ > Make sure ALL tests are passing before making a pull request. You can confirm with running `make tests`
+
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