vim-patch:8.0.1465: python2 and python3 detection not tested

Problem:    Python2 and python3 detection not tested. (Matej Cepl)
Solution:   Add test for detecting python2 and python3.  Also detect a script
            using "js" as javascript.
4bc0bed536

runtime/scripts.vim

@@ -133,7 +133,7 @@ if s:line1 =~# "^#!"
     set ft=ruby
 
     " JavaScript
-  elseif s:name =~# 'node\(js\)\=\>' || s:name =~# 'rhino\>'
+  elseif s:name =~# 'node\(js\)\=\>\|js\>' || s:name =~# 'rhino\>'
     set ft=javascript
 
     " BC calculator

src/nvim/testdir/test_filetype.vim

@@ -560,10 +560,13 @@ let s:script_checks = {
       \ 'perl6': [['#!/path/perl6']],
       \ 'perl': [['#!/path/perl']],
       \ 'php': [['#!/path/php']],
-      \ 'python': [['#!/path/python']],
+      \ 'python': [['#!/path/python'],
+      \            ['#!/path/python2'],
+      \            ['#!/path/python3']],
       \ 'groovy': [['#!/path/groovy']],
       \ 'ruby': [['#!/path/ruby']],
       \ 'javascript': [['#!/path/node'],
+      \                ['#!/path/js'],
       \                ['#!/path/nodejs'],
       \                ['#!/path/rhino']],
       \ 'bc': [['#!/path/bc']],