Handle more file closing with "with"

setup.py

@@ -138,11 +138,8 @@ else:
                                                  domain + '.js'))
 
             for js_file, (locale, po_file) in zip(js_files, po_files):
-                infile = open(po_file, 'r')
-                try:
+                with open(po_file, 'r') as infile:
                     catalog = read_po(infile, locale)
-                finally:
-                    infile.close()
 
                 if catalog.fuzzy and not self.use_fuzzy:
                     continue
@@ -159,8 +156,7 @@ else:
                             msgid = msgid[0]
                         jscatalog[msgid] = message.string
 
-                outfile = open(js_file, 'wb')
-                try:
+                with open(js_file, 'wb') as outfile:
                     outfile.write('Documentation.addTranslations(')
                     dump(dict(
                         messages=jscatalog,
@@ -168,8 +164,6 @@ else:
                         locale=str(catalog.locale)
                     ), outfile, sort_keys=True)
                     outfile.write(');')
-                finally:
-                    outfile.close()
 
     cmdclass['compile_catalog'] = compile_catalog_plusjs