Updated .gitignore to include testPeriodicBC files.

.gitignore

@@ -35,11 +35,14 @@ examples/*/*/used_parameters.yml
 examples/*/gravity_checks_*.dat
 
 tests/testPair
+tests/brute_force_periodic_BC_standard.dat
+tests/swift_periodic_BC_standard.dat
 tests/brute_force_standard.dat
 tests/swift_dopair_standard.dat
 tests/brute_force_perturbed.dat
 tests/swift_dopair_perturbed.dat
 tests/test27cells
+tests/testPeriodicBC
 tests/test125cells
 tests/brute_force_27_standard.dat
 tests/swift_dopair_27_standard.dat