Update beginner.md

[zhouwentong1993]

Create a task needs an owerEmail, Otherwise HTTP Response 400

[zhouwentong1993]

Creating Workflow Definition's HTTP request also need a ownerEmail node

[codecov]

Codecov Report

Merging #1825 into dev will decrease coverage by 0.18%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##                dev    #1825      +/-   ##
============================================
- Coverage     64.80%   64.62%   -0.19%     
+ Complexity     3826     3820       -6     
============================================
  Files           295      295              
  Lines         18180    18180              
  Branches       1653     1653              
============================================
- Hits          11782    11748      -34     
- Misses         5574     5607      +33     
- Partials        824      825       +1     

Impacted Files	Coverage Δ	Complexity Δ
...ductor/dao/cassandra/CassandraEventHandlerDAO.java	65.78% <0.00%> (-10.53%)	15.00% <0.00%> (ø%)
.../conductor/dao/cassandra/CassandraMetadataDAO.java	53.88% <0.00%> (-5.70%)	24.00% <0.00%> (-1.00%)
...ix/conductor/dao/postgres/PostgresMetadataDAO.java	76.11% <0.00%> (-5.56%)	63.00% <0.00%> (-3.00%)
...tflix/conductor/dao/postgres/PostgresQueueDAO.java	87.60% <0.00%> (-3.31%)	51.00% <0.00%> (-1.00%)
...com/netflix/conductor/service/WorkflowMonitor.java	66.66% <0.00%> (-2.23%)	5.00% <0.00%> (-1.00%)

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[coveralls]

Pull Request Test Coverage Report for Build 4426

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 33 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.2%) to 69.191%

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Files with Coverage Reduction	New Missed Lines	%
postgres-persistence/src/main/java/com/netflix/conductor/dao/postgres/PostgresQueueDAO.java	4	92.56%
cassandra-persistence/src/main/java/com/netflix/conductor/dao/cassandra/CassandraEventHandlerDAO.java	8	68.42%
cassandra-persistence/src/main/java/com/netflix/conductor/dao/cassandra/CassandraMetadataDAO.java	10	55.44%
postgres-persistence/src/main/java/com/netflix/conductor/dao/postgres/PostgresMetadataDAO.java	11	80.0%

Totals
Change from base Build 4417:	-0.2%
Covered Lines:	12579
Relevant Lines:	18180

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💛 - Coveralls