Tutorials generate erorrs

[mhpopescu]

Running tutorial_staging.py with Python 3.8.2 I get the following:

	[2021-06-16T14:26:27+0300] [MainThread] [I] [toil.worker] ---TOIL WORKER OUTPUT LOG---
	[2021-06-16T14:26:27+0300] [MainThread] [I] [toil] Running Toil version 5.3.0a1-c4476778aa867caabe7202a84e65697ff7d501eb on host lambda.
	[2021-06-16T14:26:27+0300] [MainThread] [I] [toil.worker] Working on job 'HelloWorld' kind-HelloWorld/instance-1ewqash6
	[2021-06-16T14:26:27+0300] [MainThread] [I] [toil.worker] Loaded body Job('HelloWorld' kind-HelloWorld/instance-1ewqash6) from description 'HelloWorld' kind-HelloWorld/instance-1ewqash6
	Traceback (most recent call last):
	  File "/home/lambda/toil/src/toil/worker.py", line 393, in workerScript
	    job._runner(jobGraph=None, jobStore=jobStore, fileStore=fileStore, defer=defer)
	  File "/home/lambda/toil/src/toil/job.py", line 2360, in _runner
	    returnValues = self._run(jobGraph=None, fileStore=fileStore)
	  File "/home/lambda/toil/src/toil/job.py", line 2281, in _run
	    return self.run(fileStore)
	  File "/home/lambda/toil/examples/tutorial_staging.py", line 13, in run
	    with self.fileStore.readGlobalFileStream(self.inputFileID) as fi:
	AttributeError: 'HelloWorld' object has no attribute 'fileStore'
	[2021-06-16T14:26:27+0300] [MainThread] [E] [toil.worker] Exiting the worker because of a failed job on host lambda

After I replace self.fileStore to fileStore I get:

	[2021-06-16T14:33:04+0300] [MainThread] [I] [toil.worker] ---TOIL WORKER OUTPUT LOG---
	[2021-06-16T14:33:04+0300] [MainThread] [I] [toil] Running Toil version 5.3.0a1-c4476778aa867caabe7202a84e65697ff7d501eb on host lambda.
	[2021-06-16T14:33:04+0300] [MainThread] [I] [toil.worker] Working on job 'HelloWorld' kind-HelloWorld/instance-vdzzyf07
	[2021-06-16T14:33:04+0300] [MainThread] [I] [toil.worker] Loaded body Job('HelloWorld' kind-HelloWorld/instance-vdzzyf07) from description 'HelloWorld' kind-HelloWorld/instance-vdzzyf07
	[2021-06-16T14:33:04+0300] [MainThread] [W] [toil.fileStores.abstractFileStore] Failed job accessed files:
	[2021-06-16T14:33:04+0300] [MainThread] [W] [toil.fileStores.abstractFileStore] Streamed file 'files/no-job/file-eae1da63fd154f34a70f68b2c2d90609/in.txt'
	Traceback (most recent call last):
	  File "/home/lambda/toil/src/toil/worker.py", line 393, in workerScript
	    job._runner(jobGraph=None, jobStore=jobStore, fileStore=fileStore, defer=defer)
	  File "/home/lambda/toil/src/toil/job.py", line 2360, in _runner
	    returnValues = self._run(jobGraph=None, fileStore=fileStore)
	  File "/home/lambda/toil/src/toil/job.py", line 2281, in _run
	    return self.run(fileStore)
	  File "/home/lambda/toil/examples/tutorial_staging.py", line 15, in run
	    fo.write(fi.read() + 'World!')
	TypeError: can't concat str to bytes
	[2021-06-16T14:33:04+0300] [MainThread] [E] [toil.worker] Exiting the worker because of a failed job on host lambda

The problem is that default encoding is binary and here it should have used a string encoding.

Note that self.fileStore is used in more tutorial files that this one.

┆Issue is synchronized with this Jira Task
┆Issue Number: TOIL-924

[DailyDreaming]

@mhpopescu That's odd. Generally our tutorials are actually under testing: https://github.com/DataBiosphere/toil/blob/master/src/toil/test/docs/scriptsTest.py

But tutorial_staging.py appears to be missing. Will fix it up and add it. Thanks for raising the issue!