Log errors for malformed schedule tasks-- instead of stopping schedule processing
Log errors for malformed schedule tasks-- instead of stopping schedule processing

Before when eval() would get called we'd see:
```
[ERROR   ] Exception argument of type 'NoneType' is not iterable occurred in scheduled job
```
And the schedule processing would stop (all jobs after the broken one wouldn't be run)

Now we just catch it, and skip the single job, with output like:
```
[ERROR   ] Scheduled job foo should have a dict value, not <type 'str'>
```

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt