Added file extensions to our unit test scripts to prevent MSVC from failing to...

Added file extensions to our unit test scripts to prevent MSVC from failing to build because of name clashes.

scripts/CMakeLists.txt

 get_property(EIGEN_TESTS_LIST GLOBAL PROPERTY EIGEN_TESTS_LIST)
 configure_file(buildtests.in ${CMAKE_BINARY_DIR}/buildtests @ONLY)
 
-configure_file(check.in ${CMAKE_BINARY_DIR}/check COPYONLY)
-configure_file(debug.in ${CMAKE_BINARY_DIR}/debug COPYONLY)
-configure_file(release.in ${CMAKE_BINARY_DIR}/release COPYONLY)
+configure_file(check.in ${CMAKE_BINARY_DIR}/check.sh COPYONLY)
+configure_file(debug.in ${CMAKE_BINARY_DIR}/debug.sh COPYONLY)
+configure_file(release.in ${CMAKE_BINARY_DIR}/release.sh COPYONLY)