Removed extra spaces, type checking callback when constructed

.travis.yml

@@ -5,4 +5,3 @@ node_js:
   - "iojs"
 before_script: npm run lint
 script: ./node_modules/.bin/istanbul cover ./node_modules/.bin/nodeunit test && cat ./coverage/lcov.info | ./node_modules/.bin/coveralls && rm -rf ./coverage
-

lib/schedule.js

@@ -25,10 +25,10 @@ function Job(name, job, callback) {
   // Make sure callback is actually a callback
   if (this.job === name) {
     // Name wasn't provided and maybe a callback is there
-    this.callback = job || false;
+    this.callback = typeof job === 'function' ? job : false;
   } else {
     // Name was provided, and maybe a callback is there
-    this.callback = callback || false;
+    this.callback = typeof callback === 'function' ? callback : false;
   }
 
   // define properties
@@ -383,7 +383,7 @@ function prepareNextInvocation() {
     currentInvocation.timerID = runOnDate(currentInvocation.fireDate, function() {
       currentInvocationFinished();
 
-      if (job.callback && typeof job.callback === 'function') {
+      if (job.callback) {
         job.callback();
       }
 

test/convenience-method-test.js

@@ -255,7 +255,6 @@ module.exports = {
         test.ok(true);
       });
 
-
       setTimeout(function() {
         schedule.cancelJob(job.name);
       }, 2250);