Repository: python-visualization/folium

Issue:
Styling Imported Images
New to Python, kinda dove into it headfirst to create an interactive map with data. Really enjoying it, and really loving what Folium can do.

I've added a legend.png to create a legend (temporarily, or perhaps permanently, unless something else can be recommended) that I'd like to style by adding a box-shadow as well as adding a radius to curve the edges if I so desire.

Perhaps it's already in the notes somewhere, but I couldn't find it!

The legend itself works as it should and doesn't interfere with interacting with each site bubble (each site is expected to have more than just a "name" at some point. Actual data/graphs/etc. will be contained for nearly each site.)

```python
# Create Map Legend
from folium.plugins import FloatImage
image_file='images/Legend.png'

FloatImage(image_file,bottom=5,left=5).add_to(map)

```

Another quick question: can the output HTML file be modified with a viewport tag to assist with scaling on a mobile environment? I haven't tried it yet, and I assume each time I compile the app after I make changes the subsequent HTML file is entirely overwritten.

Thank you!



Discussion:
beautah: I chased down the all the failed checks and the remaining seem to be not related to any changes I've made. Happy to fix anything else up if needed though

Patch:
diff --git a/folium/plugins/float_image.py b/folium/plugins/float_image.py
index 00f32e03..fd3fc21f 100644
--- a/folium/plugins/float_image.py
+++ b/folium/plugins/float_image.py
@@ -12,6 +12,7 @@ class FloatImage(MacroElement):
                         position:absolute;
                         bottom:{{this.bottom}}%;
                         left:{{this.left}}%;
+                        width:{{this.width}}%;
                         }
                 </style>
             {% endmacro %}
@@ -24,9 +25,10 @@ class FloatImage(MacroElement):
             {% endmacro %}
             """)
 
-    def __init__(self, image, bottom=75, left=75):
+    def __init__(self, image, bottom=75, left=75, width=100):
         super(FloatImage, self).__init__()
         self._name = 'FloatImage'
         self.image = image
         self.bottom = bottom
         self.left = left
+        self.width = width


Test patch:
diff --git a/tests/plugins/test_float_image.py b/tests/plugins/test_float_image.py
index 8fdf02f4..cf98028e 100644
--- a/tests/plugins/test_float_image.py
+++ b/tests/plugins/test_float_image.py
@@ -13,7 +13,7 @@ from jinja2 import Template
 def test_float_image():
     m = folium.Map([45., 3.], zoom_start=4)
     url = 'https://raw.githubusercontent.com/SECOORA/static_assets/master/maps/img/rose.png'
-    szt = plugins.FloatImage(url, bottom=60, left=70)
+    szt = plugins.FloatImage(url, bottom=60, left=70, width=20)
     m.add_child(szt)
     m._repr_html_()
 
@@ -35,6 +35,7 @@ def test_float_image():
                 position:absolute;
                 bottom:60%;
                 left:70%;
+                width:20%;
                 }
         </style>
     """)