Changed open_energy to use MDAnalysis instead of Gromacs energy tool.

mdevaluate/__init__.py

@@ -94,11 +94,9 @@ def open(
     return coords
 
 
-def open_energy(file, energies=None):
+def open_energy(file):
     """Reads an gromacs energy file and output the data in a pandas DataFrame.
     Args:
         file: Filename of the energy file
-        energies (opt.): Specify energies to extract from the energy file
     """
-    df = reader.energy_reader(file, energies=energies)
-    return df
+    return reader.energy_reader(file)