Remove traces of spm since that project has been deprecated

[spm](https://github.com/spmjs/spm) seems to have been stale for 4 years
and has a deprecation warning in its github repository.

hooks/pre-commit

@@ -47,7 +47,7 @@ class Bumper
 			# notify codemonkey
 			puts "staged bumped files and created commit"
 			puts_c 32, "successfully bumped version to #{@target_v}!"
-			puts_c 33, "don't forget to `npm publish` and `spm publish`!"
+			puts_c 33, "don't forget to `npm publish`!"
 		end
 
 		exit 0

package.json

@@ -48,13 +48,6 @@
     "zuul": "^3.11.0",
     "zuul-ngrok": "nolanlawson/zuul-ngrok#patch-1"
   },
-  "spm": {
-    "main": "mustache.js",
-    "ignore": [
-      "test",
-      "wrappers"
-    ]
-  },
   "greenkeeper": {
     "ignore": [
       "eslint"