GitHub Actions CI

[gbarbon]

This PR introduces the GitHub Actions continuous integration to Kapua.

Related Issue
This PR partially fixes #3181

Description of the solution adopted
A workflows/github-actions.yaml script its added to the .github/ directory, and allows triggering the GitHub Actions on the Kapua project and its forks. Such yaml files is similar to the travis.yaml one, and allows having multiple jobs that performs in parallel all the integration testing phases.

Screenshots
n/a

Any side note on the changes made
This PR does not remove the Travis CI integration (another PR is required for that), since the two (Travis CI and GitHub Actions) should be used in parallel for a period, in order to be sure that the results of GitHub actions are correct.

[codecov]

Codecov Report

Merging #3182 (c3dd121) into develop (ba51416) will increase coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             develop    #3182   +/-   ##
==========================================
  Coverage      63.05%   63.06%           
+ Complexity      2488     2485    -3     
==========================================
  Files           1118     1118           
  Lines          23146    23146           
  Branches        2004     2004           
==========================================
+ Hits           14595    14597    +2     
+ Misses          7630     7626    -4     
- Partials         921      923    +2     

Impacted Files	Coverage Δ	Complexity Δ
...rtz/persistence/KapuaQuartzConnectionProvider.java	87.50% <0.00%> (-12.50%)	4.00% <0.00%> (-1.00%)
...pse/kapua/broker/core/pool/JmsConsumerWrapper.java	60.00% <0.00%> (-10.00%)	0.00% <0.00%> (ø%)
...ua/broker/core/listener/DeviceMessageListener.java	60.46% <0.00%> (-6.98%)	0.00% <0.00%> (ø%)
...ce/management/commons/call/DeviceCallExecutor.java	62.79% <0.00%> (-4.66%)	0.00% <0.00%> (ø%)
.../DeviceManagementOperationRegistryServiceImpl.java	66.07% <0.00%> (-3.58%)	12.00% <0.00%> (-2.00%)
.../broker/core/plugin/KapuaSecurityBrokerFilter.java	74.85% <0.00%> (+0.28%)	0.00% <0.00%> (ø%)
...plugin/authentication/UserAuthenticationLogic.java	83.03% <0.00%> (+1.78%)	0.00% <0.00%> (ø%)
...a/org/eclipse/kapua/transport/mqtt/MqttClient.java	62.19% <0.00%> (+6.09%)	0.00% <0.00%> (ø%)
...ransport/mqtt/pooling/PooledMqttClientFactory.java	71.42% <0.00%> (+9.52%)	0.00% <0.00%> (ø%)