add link

docs/test.md

 
 #Testing environment
 
-You can check the environment with tests.
+Previously [install](https://github.com/frankiejol/Test-SQL-Data/blob/master/INSTALL.md) TEST::SQL::DATA module.
+
+In project root run:
 
     $ perl Makefile.PL
     $ sudo make test 
@@ -11,10 +13,3 @@ At the end, in "Test Summary Report" you can check the result.
 If something goes wrong you see: 
     Result: FAIL    
 
-
-#Library TEST::SQL::DATA
-For install TEST::SQL::DATA module follow the instructions below:
-
-    https://github.com/frankiejol/Test-SQL-Data/blob/master/INSTALL.md
-
-