Fix imports of windpowerlib

Author: birgits

example/basic_example.py

@@ -14,8 +14,8 @@
 except ImportError:
     plt = None
 
-from windpowerlib.modelchain import ModelChain
-from windpowerlib.wind_turbine import WindTurbine
+from windpowerlib import ModelChain
+from windpowerlib import WindTurbine
 
 # You can use the logging package to get logging messages from the windpowerlib
 # Change the logging level if you want more or less messages

windpowerlib/__init__.py

@@ -1,3 +1,14 @@
 __copyright__ = "Copyright oemof developer group"
 __license__ = "GPLv3"
-__version__ = '0.0.6'
+__version__ = '0.0.6'
+
+from windpowerlib import density
+from windpowerlib import modelchain
+from windpowerlib import power_output
+from windpowerlib import temperature
+from windpowerlib import tools
+from windpowerlib import wind_speed
+from windpowerlib import wind_turbine
+
+from windpowerlib.wind_turbine import WindTurbine
+from windpowerlib.modelchain import ModelChain