Update version number and ribbon colour for alpha-18

editions/tw5.com/tiddlers/system/github-fork-ribbon.tid

@@ -1,5 +1,5 @@
 title: $:/editions/tw5.com/github-fork-ribbon
 tags: $:/tags/PageTemplate
 
-<div class="github-fork-ribbon-wrapper right" style><div class="github-fork-ribbon" style="background-color:#41BD23;"><$link to="ReleaseHistory"><<version>></$link></div>
+<div class="github-fork-ribbon-wrapper right" style><div class="github-fork-ribbon" style="background-color:#A3D53A;"><$link to="ReleaseHistory"><<version>></$link></div>
 </div>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "tiddlywiki",
   "preferGlobal": "true",
-  "version": "5.0.0-alpha.17",
+  "version": "5.0.0-alpha.18-prerelease",
   "author": "Jeremy Ruston <jeremy@jermolene.com>",
   "description": "a non-linear personal web notebook",
   "contributors": [