have failed compiles warn rather than be an error

services/clsi/app/coffee/CompileController.coffee

@@ -33,7 +33,7 @@ module.exports = CompileController =
 						else
 							status = "error"
 							code = 500
-							logger.error err: error, project_id: request.project_id, "error running compile"
+							logger.warn err: error, project_id: request.project_id, "error running compile"
 
 					else
 						status = "failure"
@@ -42,7 +42,7 @@ module.exports = CompileController =
 								status = "success"
 								
 						if status == "failure"
-							logger.err project_id: request.project_id, outputFiles:outputFiles, "project failed to compile successfully, no output.pdf generated"
+							logger.warn project_id: request.project_id, outputFiles:outputFiles, "project failed to compile successfully, no output.pdf generated"
 
 						# log an error if any core files are found
 						for file in outputFiles

services/clsi/test/unit/coffee/CompileControllerTests.coffee

@@ -14,7 +14,7 @@ describe "CompileController", ->
 					clsi:
 						url: "http://clsi.example.com"
 			"./ProjectPersistenceManager": @ProjectPersistenceManager = {}
-			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub(), err:sinon.stub() }
+			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub(), err:sinon.stub(), warn: sinon.stub()}
 		@Settings.externalUrl = "http://www.example.com"
 		@req = {}
 		@res = {}