Bump pairs version

Author: sharkdp

.gitignore

@@ -2,3 +2,4 @@
 /.spago
 /output
 /.purs-repl
+/bower_components

bower.json

@@ -22,7 +22,7 @@
         "purescript-newtype": "^v5.0.0",
         "purescript-nonempty": "^v7.0.0",
         "purescript-numbers": "^v9.0.0",
-        "purescript-pairs": "^v8.0.0",
+        "purescript-pairs": "^v9.0.0",
         "purescript-prelude": "^v6.0.0",
         "purescript-tuples": "^v7.0.0"
     }