Fix imports

Author: austin-hoover

orbit_tools/linac/diag.py

@@ -7,6 +7,8 @@
 
 from orbit.core import orbit_mpi
 from orbit.core.bunch import Bunch
+from orbit.core.bunch import BunchTwissAnalysis
+from orbit.core.orbit_utils import BunchExtremaCalculator
 from orbit.lattice import AccLattice
 from orbit.lattice import AccNode