Moving the installation of CPPCHECK and CLANG-FORMAT to .travis.yml

[lekshmideepu]

As we have $xSTATIC_ANALYSIS enabled for all our builds, do we need this ?

Also I think we could move the installations of CPPCHECK and CLANG-FORMAT from build.sh to the package installation section in .travis.yml where we install all the other packages.

[lekshmideepu]

I have successfully moved the installation to the yaml file and the build is fine except the final build summary table as it depends on the MSGBLDxxxx numbers created by @gtrensch
Made necessary changes in the build.sh file and have to do the changes in extras/parse_travis_log.py

[gtrensch]

Generally, moving all the installation to the yml-file is a good idea. $STATIC_ANALYSIS is always set in the build matrix and can probably be removed too.

The MSGBLDxxxx message numbers indicate the status of the code analysis tool installation process. They are needed to evaluate the build by the parser script.

[gtrensch]

@lekshmideepu A note on the message numbers: Parsing log files or console outputs is always a proplem. From a software engineering perspective it introduces dependencies and a coupling which you actually want to avoid. The previous implementation relied on the message texts itself. Means, fixing a typo could mess up the log parser. So I intruduced the numbers. You may move and change the messages but not the mumbers. If so doing, you need to take care of their dependencies with the python log parser.

[heplesser]

Fixed by #789.