Added integration with Travis-CI deployments and test execution.

[jgebal]

Important notice

You will need to update the follwing to make integrations work for you:

• signup onto travis and enable repo integration
• signup to dockerhub and do one of
  • ask me for access to our docker repo for DB images
  • create your own images in private repo (see: https://github.com/utPLSQL/docker-scripts or https://github.com/oracle/docker-images/tree/master/OracleDatabase)
• set secret env variables
  - DOCKER_USER - Your Dockerhub user
  - DOCKER_PASSWORD - Your Dockerhub PASS
  - ORACLE_OTN_USER - Your Oracle Tech Net user
  - ORACLE_OTN_PASSWORD - Your Oracle Tech Net PASS
  - DB_SYS_PASSWORD - SYS account password for DB
  - SONAR_TOKEN - if you want to use sonarcloud.io for static code analysis and publishing of test results - see https://docs.travis-ci.com/user/sonarcloud/
• to make sonarcloud integration, signup to sonarcloud with your github account and configure it. It's actually pretty simple.
• you will also need to update badges in readme.md, snarcloud organization in travis.yml and sonar-project.properties (they all point to jgebal/Logger repo)

Content

Added integration with sonarcloud.io
Converted and added test package as utPLSQL v3 unit test.
The change includes:

testing deployment of Logger in automated fashion on each commit
running tests and showing test results in Travis-CI
exporting test results and coverage into sonar
performing static code analysis in sonar
Additional badges for sonar and travis were added to readme.md
For details on integration see:
https://www.sonarcloud.io/documentation/integrations/github/
https://docs.travis-ci.com/user/sonarcloud/

To see the integration working on my github see:

• badges integrated with readme: https://github.com/jgebal/Logger/blob/3.2.0/README.md
• sonarcloud analysis: https://sonarcloud.io/dashboard?id=jgebal_Logger
• Travis builds: https://travis-ci.org/jgebal/Logger/builds
• Travis build log indicating a failing test: https://travis-ci.org/jgebal/Logger/jobs/540434451#L3313
• Travis notifications on Pull requests: Added integration with Travis-CI deployments and test execution. jgebal/Logger#1 https://github.com/jgebal/Logger/runs/140210253

[jgebal]

@martindsouza - any chance to get this PR reviewed?