Removed extra information from RCS keyword strings in tests

Version numbers and dates (mostly wrong) from RCS keyword strings
removed from all test files; only the file name are kept.

testes/api.lua

@@ -1,4 +1,4 @@
--- $Id: testes/api.lua 2018-07-25 15:31:04 -0300 $
+-- $Id: testes/api.lua $
 -- See Copyright Notice in file all.lua
 
 if T==nil then

testes/coroutine.lua

@@ -1,4 +1,4 @@
--- $Id: testes/coroutine.lua 2018-07-25 15:31:04 -0300 $
+-- $Id: testes/coroutine.lua $
 -- See Copyright Notice in file all.lua
 
 print "testing coroutines"

testes/events.lua

@@ -1,4 +1,4 @@
--- $Id: testes/events.lua 2018-07-25 15:31:04 -0300 $
+-- $Id: testes/events.lua $
 -- See Copyright Notice in file all.lua
 
 print('testing metatables')

testes/math.lua

@@ -1,4 +1,4 @@
--- $Id: testes/math.lua 2018-07-25 15:31:04 -0300 $
+-- $Id: testes/math.lua $
 -- See Copyright Notice in file all.lua
 
 print("testing numbers and math lib")