Maven cleanup + automation of release tasks

[slanglois]

Maven pom cleanup:

• Removing the parent pom
• Adding / upgrading project metadata
• Upgrading Maven plugins
• Removing useless distro profile

Automating releases:

• include distribution URLs (snapshot and release)
• configuration of the maven-release-plugin

[slanglois]

The build keeps failing in OutOfMemory on Travis, always on the same test:

[INFO] Running org.activiti.engine.test.bpmn.gateway.InclusiveGatewayDefaultFlowTest
Exception in thread "Thread-8" java.lang.OutOfMemoryError: GC overhead limit exceeded
	at java.util.Arrays.copyOf(Arrays.java:3332)
	at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:124)
	at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:596)
	at java.lang.StringBuffer.append(StringBuffer.java:367)
	at java.io.BufferedReader.readLine(BufferedReader.java:370)
	at java.io.BufferedReader.readLine(BufferedReader.java:389)
	at org.apache.maven.surefire.shade.org.apache.maven.shared.utils.cli.StreamPumper.run(StreamPumper.java:76)
Exception in thread "ThreadedStreamConsumer" java.lang.OutOfMemoryError: GC overhead limit exceeded

I've tried setting -Xmx256m on the forked JVM, but I get the same error.
I updated the maven-surefire-plugin so it may behave a bit differently, but hopefully not that badly...
I may need your help to understand what's going on there.

[daisuke-yoshimoto]

@slanglois
I think you may be able to set JVM parameter of Junit process in .travis.yml.
-DsurefireArgLine="-Xmx256m"

But, you need to restore the following change.
https://github.com/Activiti/Activiti/blob/master/pom.xml#L557
https://github.com/Activiti/Activiti/pull/1263/files#diff-600376dffeb79835ede4a0b285078036L557

[slanglois]

Thanks @daisuke-yoshimoto
I'd rather not bring this change back... It's not standard and I find it clumsy.
The standard way to specify this is through the argLine property, like in d5322d0
Moreover, I'd rather do this change in the POM rather than .travis.yml, so that everyone benefits from it.

Anyway, the memory problem was actually not in the forked JVM, which runs the tests, but in the one running Maven itself.
I fixed this by setting the MAVEN_OPTS env variable on Travis.
It's all good now :-)

[codecov]

Codecov Report

Merging #1263 into master will increase coverage by 5.75%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1263      +/-   ##
============================================
+ Coverage     56.75%   62.51%   +5.75%     
- Complexity     9228     9235       +7     
============================================
  Files          1149     1010     -139     
  Lines         40795    37065    -3730     
  Branches       5928     5422     -506     
============================================
+ Hits          23155    23170      +15     
+ Misses        14913    11170    -3743     
+ Partials       2727     2725       -2

Impacted Files	Coverage Δ	Complexity Δ
...xecutionsWithSameRootProcessInstanceIdMatcher.java	25% <0%> (-12.5%)	3% <0%> (-1%)
...validation/validator/impl/ScriptTaskValidator.java
...rg/activiti/bpmn/model/MessageEventDefinition.java
...main/java/org/activiti/bpmn/model/ServiceTask.java
.../java/org/activiti/bpmn/model/ParallelGateway.java
...iti/validation/validator/impl/SignalValidator.java
...ion/validator/impl/ExecutionListenerValidator.java
.../org/activiti/bpmn/model/ErrorEventDefinition.java
...src/main/java/org/activiti/bpmn/model/Process.java
...va/org/activiti/bpmn/model/DataStoreReference.java
... and 136 more

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[erdemedeiros]

Great job! It seems we were missing some coverage reports before (5.75% more).