Merge pull request #241 from common-workflow-language/mr-c-patch-1

typo: instal -> install

Author: mr-c

README.rst

@@ -28,7 +28,7 @@ well)::
 
 If installling alongside another CWL implementation then::
 
-  pip instal cwltool
+  pip install cwltool
 
 To install from source::