[AIRFLOW-3933] Fix various typos

[ryanyuan]

Fix typos

Make sure you have checked all steps below.

Jira

• My PR addresses the following Airflow-3933 issues and references them in the PR title. For example, "[AIRFLOW-XXX] My Airflow PR"

Description

• Here are some details about my PR, including screenshots of any UI changes:

Commits

• My commits all reference Jira issues in their subject lines, and I have squashed multiple commits if they address the same issue. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Code Quality

• Passes flake8

[zhongjiajie]

@ryanyuan Awesome!

[drewsonne]

Not sure what the convention is, but maybe should be capitalised?

[drewsonne]

I think it should be GitHub

[codecov-io]

Codecov Report

Merging #4747 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master    #4747   +/-   ##
=======================================
  Coverage   74.61%   74.61%           
=======================================
  Files         430      430           
  Lines       28009    28009           
=======================================
  Hits        20900    20900           
  Misses       7109     7109

Impacted Files	Coverage Δ
...ow/contrib/example_dags/example_qubole_operator.py	0% <ø> (ø)	⬆️
airflow/operators/presto_check_operator.py	0% <ø> (ø)	⬆️
airflow/contrib/hooks/salesforce_hook.py	0% <ø> (ø)	⬆️
airflow/contrib/hooks/azure_data_lake_hook.py	92.85% <ø> (ø)	⬆️
airflow/contrib/operators/cassandra_to_gcs.py	63.31% <ø> (ø)	⬆️
airflow/contrib/operators/dataflow_operator.py	100% <ø> (ø)	⬆️
airflow/contrib/hooks/qubole_hook.py	53.65% <ø> (ø)	⬆️
airflow/contrib/hooks/fs_hook.py	90% <ø> (ø)	⬆️
airflow/contrib/operators/awsbatch_operator.py	83.33% <ø> (ø)	⬆️
...rflow/contrib/operators/bigquery_check_operator.py	0% <ø> (ø)	⬆️
... and 3 more

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov-io]

Codecov Report

Merging #4747 into master will decrease coverage by <.01%.
The diff coverage is 33.33%.

@@            Coverage Diff             @@
##           master    #4747      +/-   ##
==========================================
- Coverage   74.61%   74.61%   -0.01%     
==========================================
  Files         430      430              
  Lines       28009    28009              
==========================================
- Hits        20900    20899       -1     
- Misses       7109     7110       +1

Impacted Files	Coverage Δ
...ow/contrib/example_dags/example_qubole_operator.py	0% <ø> (ø)	⬆️
airflow/operators/presto_check_operator.py	0% <ø> (ø)	⬆️
airflow/contrib/hooks/salesforce_hook.py	0% <ø> (ø)	⬆️
airflow/contrib/hooks/azure_data_lake_hook.py	92.85% <ø> (ø)	⬆️
airflow/contrib/operators/cassandra_to_gcs.py	63.31% <ø> (ø)	⬆️
airflow/contrib/operators/dataflow_operator.py	100% <ø> (ø)	⬆️
airflow/contrib/hooks/qubole_hook.py	53.65% <ø> (ø)	⬆️
airflow/contrib/hooks/fs_hook.py	90% <ø> (ø)	⬆️
airflow/contrib/operators/awsbatch_operator.py	83.33% <ø> (ø)	⬆️
...rflow/contrib/operators/bigquery_check_operator.py	0% <ø> (ø)	⬆️
... and 5 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c7d6c1a...bd44117. Read the comment docs.

[XD-DENG]

@ryanyuan awesome!

A minor minor suggestion: if all changes in your PR are purely doc change, you can add "[ci skip]" in your git commit message to skip the CI, so that it can save ASF a small amount of money.

[zhongjiajie]

@XD-DENG I donnot know CI test need money before. Isn't travis-ci free for open source project?

[XD-DENG]

Hi @zhongjiajie , Yes it is free for open source projects, but for relatively small size ones. If you integrate your Airflow fork with TravisCI, you will find that it's free but you can only run 5 tests concurrently.

ASF is using a subscribed service from Travis so Apache projects like Airflow's CI on Travis can run "unlimited" concurrent tests. It's not free in that case.

I got to know this from Ash earlier: #3967 (comment) (both "[ci skip]" and "[skip ci]" would work I remember)

[ryanyuan]

@XD-DENG Thanks for the tips!

[zhongjiajie]

@XD-DENG I get this, thanks.

[Fokko]

Thanks @ryanyuan