Durther minor edits for attribution functionality

Author: darribas

contextily/__init__.py

@@ -5,6 +5,6 @@
 from . import tile_providers as sources
 from .place import Place, plot_map
 from .tile import *
-from .plotting import add_basemap, add_legend
+from .plotting import add_basemap, add_attribution
 
 __version__ = '0.99.0.dev'

contextily/plotting.py

@@ -120,7 +120,7 @@ def add_attribution(ax, att=ATTRIBUTION):
     minY, maxY = ax.get_ylim()
     ax.text(minX + (maxX - minX) * 0.005, 
             minY + (maxY - minY) * 0.005, 
-            lic, size=8, 
+            att, size=8, 
             path_effects=[patheffects.withStroke(linewidth=2,
                                                  foreground="w")])
     return ax