Try to fix Windows tests

test/fix/test_ale_fix.vader

@@ -221,7 +221,7 @@ Execute(Should apply filename mpapings):
   " that ALEFix applies filename mappings, end-to-end.
   let g:ale_filename_mappings = {
   \ 'echo_filename': [
-  \   [expand('%:p:h'), '/some/fake/path'],
+  \   [expand('%:p:h') . '/', '/some/fake/path/'],
   \ ],
   \}
 

test/test_filename_mapping.vader

@@ -56,7 +56,7 @@ Execute(ale#filename_mapping#Map should map filenames):
   AssertEqual
   \ '/data/bar',
   \ ale#filename_mapping#Map('/foo//bar', [
-  \   ['/data', '/baz'],
-  \   ['/foo', '/data'],
-  \   ['/foo', '/xyz'],
+  \   ['/data/', '/baz/'],
+  \   ['/foo/', '/data/'],
+  \   ['/foo/', '/xyz/'],
   \ ])