Add compact import (#59)

Author: martinateruzzi

grape/__init__.py

@@ -22,6 +22,6 @@ def get_current_year():
 __maintainer__ = __author__
 __status__ = "Alpha"
 
-from .general_graph import GeneralGraph
-from .parallel_general_graph import ParallelGeneralGraph
-from .fault_diagnosis import FaultDiagnosis
+from grape.general_graph import GeneralGraph
+from grape.parallel_general_graph import ParallelGeneralGraph
+from grape.fault_diagnosis import FaultDiagnosis