Removal of empty test directories

tests/CMakeLists.txt

-# Large test, employing the full simulator. 
-# validated using deltas on output data
-add_subdirectory(delta)
-
-# Test for the internode communication (eg. mpi)
-add_subdirectory(global_communication)
-
-# Test to check integration between components of the site_name
-add_subdirectory(integration)
-
-# Check for performance: This could include stand alone tests
-# These do not necessarily be run automatically
-add_subdirectory(performance)
-
-# Numbered tests based on bugs in the tracker
-add_subdirectory(regression)
 
 # google test framework
 add_library(gtest gtest-all.cpp)
-
 # tests look for gtest.h here
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
+
 # Unit tests
 add_subdirectory(unit)
 
 # Test validating models, possebly needing other software installed
 add_subdirectory(validation)
+
+# Test for the internode communication (eg. mpi)
+add_subdirectory(global_communication)
+
+
+# Proposed additional test types:
+
+# Large test, employing the full simulator. validated using deltas on output data
+
+# Test to check integration between components 
+
+# Tests for performance: This could include stand alone tests. These do not necessarily be run automatically
+
+# Numbered tests based on bugs in the tracker
+

tests/delta/CMakeLists.txt

-# Nothing to be done yet

tests/integration/CMakeLists.txt

-# Nothing to be done yet

tests/performance/CMakeLists.txt

-# Nothing to be done yet

tests/regression/CMakeLists.txt

-# Nothing to be done yet