Remove engines

Node v0.6 is pretty much gone at this point.  Also, the -pre upsets
SemVer 4, making it annoying to test npm on Node in development.

bin/npm-cli.js

@@ -61,12 +61,6 @@ log.info("using", "node@%s", process.version)
 // make sure that this version of node works with this version of npm.
 var semver = require("semver")
   , nodeVer = process.version
-  , reqVer = npm.nodeVersionRequired
-if (reqVer && !semver.satisfies(nodeVer, reqVer)) {
-  return errorHandler(new Error(
-    "npm doesn't work with node " + nodeVer
-    + "\nRequired: node@" + reqVer), true)
-}
 
 process.on("uncaughtException", errorHandler)
 

lib/npm.js

@@ -44,16 +44,6 @@ try {
   var j = JSON.parse(fs.readFileSync(
     path.join(__dirname, "../package.json"))+"")
   npm.version = j.version
-  npm.nodeVersionRequired = j.engines.node
-  if (!semver.satisfies(pv, j.engines.node)) {
-    log.warn("unsupported version", [""
-            ,"npm requires node version: "+j.engines.node
-            ,"And you have: "+pv
-            ,"which is not satisfactory."
-            ,""
-            ,"Bad things will likely happen.  You have been warned."
-            ,""].join("\n"))
-  }
 } catch (ex) {
   try {
     log.info("error reading version", ex)

package.json

@@ -157,9 +157,6 @@
     "require-inject": "~1.0.0",
     "tap": "~0.4.12"
   },
-  "engines": {
-    "node": ">=0.8"
-  },
   "scripts": {
     "test-legacy": "node ./test/run.js",
     "test": "tap --timeout 120 test/tap/*.js",