Update fs from 2.4.5 to 2.4.8
diff --git a/requirements.txt b/requirements.txt
index bdfd52b..8e1fe6e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,4 +8,4 @@
 munkres==1.0.12; platform_python_implementation == "PyPy" and python_version < '3.5'  # pyup: ignore
 munkres==1.1.2; platform_python_implementation == "PyPy" and python_version >= '3.5'
 zopfli==0.1.6
-fs==2.4.5
+fs==2.4.8