Fix for plot_evolve() string argument (#4639)

utils/plots.py

@@ -358,8 +358,9 @@ def profile_idetection(start=0, stop=0, labels=(), save_dir=''):
     plt.savefig(Path(save_dir) / 'idetection_profile.png', dpi=200)
 
 
-def plot_evolve(evolve_csv=Path('path/to/evolve.csv')):  # from utils.plots import *; plot_evolve()
+def plot_evolve(evolve_csv='path/to/evolve.csv'):  # from utils.plots import *; plot_evolve()
     # Plot evolve.csv hyp evolution results
+    evolve_csv = Path(evolve_csv)
     data = pd.read_csv(evolve_csv)
     keys = [x.strip() for x in data.columns]
     x = data.values