wrap tests in module BlackBoxOptimTests ... end

could improve type inference for top-level objects and allow
running tests using `reload()`

Author: alyst

test/runtests.jl

@@ -1,3 +1,5 @@
+module BlackBoxOptimTests
+
 include("helper.jl")
 
 import Compat.String
@@ -43,3 +45,5 @@ for t in my_tests
 end
 
 exitstatus()
+
+end # module BlackBoxOptimTests