Fix incorrect import due to refactoring of observers

Author: stijnh

kernel_tuner/energy/energy.py

@@ -6,7 +6,7 @@
 
 import numpy as np
 from kernel_tuner import tune_kernel, util
-from kernel_tuner.nvml import NVMLObserver, get_nvml_gr_clocks
+from kernel_tuner.observers.nvml import NVMLObserver, get_nvml_gr_clocks
 from scipy import optimize
 
 try:

test/test_nvml_mocked.py

@@ -5,7 +5,7 @@
 except ImportError:
     from unittest.mock import patch, Mock
 
-from kernel_tuner.nvml import get_nvml_pwr_limits, get_nvml_gr_clocks, get_nvml_mem_clocks, get_idle_power
+from kernel_tuner.observers.nvml import get_nvml_pwr_limits, get_nvml_gr_clocks, get_nvml_mem_clocks, get_idle_power