Don't put docs which are already in s3 through archive job

This fixes the bug we saw with 'RangeError: Maximum call stack size exceeded'
if lots of docs are already in s3 cb() gets called synchronously multiple times quickly
which can cause the execption. I am not sure where the recursion is, maybe inside async.

doing setImmediate(cb) also fixes the issue as I beilve it gives the
process chance to clear the stack. Similar to process.nextTick

services/docstore/app/coffee/DocArchiveManager.coffee

@@ -16,12 +16,10 @@ module.exports = DocArchive =
 				return callback(err)
 			else if !docs?
 				return callback new Errors.NotFoundError("No docs for project #{project_id}")
+			docs = _.filter docs, (doc)-> doc.inS3 != true
 			jobs = _.map docs, (doc) ->
-				(cb)-> 
-					if doc.inS3
-						return cb()
-					else
-						DocArchive.archiveDoc project_id, doc, cb
+				(cb)->
+					DocArchive.archiveDoc project_id, doc, cb
 			async.series jobs, callback
 
 

services/docstore/test/unit/coffee/DocArchiveManager.coffee

@@ -168,7 +168,7 @@ describe "DocArchiveManager", ->
 
 			it "should not throw and error", (done)->
 				@DocArchiveManager.archiveAllDocs @project_id, (err)=>
-					err.should.not.exist
+					should.not.exist err
 					done()