Resolve "(LearnerND) add iso-surface plot feature"

Closes #112 (closed)

adaptive/notebook_integration.py

@@ -25,14 +25,14 @@ def notebook_extension():
             holoviews.notebook_extension('bokeh')
             _holoviews_enabled = True
     except ModuleNotFoundError:
-        warnings.warn("holoviews are not installed; plotting "
+        warnings.warn("holoviews is not installed; plotting "
                       "is disabled.", RuntimeWarning)
     try:
         if not _ipywidgets_enabled:
             import ipywidgets
             _ipywidgets_enabled = True
     except ModuleNotFoundError:
-        warnings.warn("ipywidgets are not installed; plotting "
+        warnings.warn("ipywidgets is not installed; live_info "
                       "is disabled.", RuntimeWarning)
 
     if not _async_enabled: