bump deps, handle DEP0005, make npm audit happy

The "new Buffer(…)" usages have been fixed to non-deprecated
"Buffer.from(…)". The npm audit report container a vulnerabiility
for a lib that was used by nodeunit – that's why a specific sshpk
version is being mentioned in the devDependencies and nodeunit was moved
to that section as well. Updated changelog and shrinkwrap file and
allowed more engine versions in package file as tests run on all node
versions from 4.x up to current edge version of 12.x. refs #138

CHANGELOG.md

@@ -3,8 +3,12 @@
 ## 2.7.9 (2019-03-25)
 
 * fixed: too many folder levels for docker to cope with (see [Issue 138](https://github.com/berlinonline/converjon/issues/138))
+* fixed: Usages of ``new Buffer(…)`` have been changed to ``Buffer.from(…)`` – see [DEP0005](https://nodejs.org/en/docs/guides/buffer-constructor-deprecation/) for more info
+* bumped node engine version in `package.json` to support more versions – `npm test` succeed for v4.x up to edge v12 atm
+* bumped dependencies
+* moved `nodeunit` dep into `devDependencies` - it's deprecated and using a specific `sshpk` lib version was necessary to reach `npm audit` result of 0 known vulnerabilities
 
-*Beware*: The change of the internal `cache` folder structure means, that your cache is invalidated upon deployment of this version. This shouldn't affect your apps too much as long as you took the hint of running converjon behind a caching reverse proxy. Keep it in mind though when switching to this version as you cache folder size may double.
+*Beware*: The change of the internal `cache` folder structure means, that your cache is invalidated upon deployment of this version. This shouldn't affect your apps too much as long as you took the hint of running converjon behind a caching reverse proxy. Keep it in mind though when switching to this version as your cache folder size may double.
 
 ## 2.7.8 (2018-08-02)
 

lib/pathutils.js

@@ -24,7 +24,7 @@ function replaceAll(string, omit, place, prevstring) {
 exports.join = join;
 
 exports.getHashPath = function(input) {
-    var hash = crypto.createHash('sha256').update(new Buffer(input)).digest("hex");
+    var hash = crypto.createHash('sha256').update(Buffer.from(input)).digest("hex");
     return hash.substr(0, 2)+path_sep+hash;
 };
 
@@ -43,5 +43,5 @@ exports.getOptionsPath = function(options) {
         return "__no_options";
     }
 
-    return crypto.createHash('sha256').update(new Buffer(join(path_parts))).digest("hex");
+    return crypto.createHash('sha256').update(Buffer.from(join(path_parts))).digest("hex");
 };