Travis-CI test should run from now on

I am using the new feature to test under different operation systems.

Therefore, we should be able to guarantee that the SeqChunker works under Linux and MacOSX

According to https://docs.travis-ci.com/user/customizing-the-build/#Customizing-the-Installation-Step the installation step to resolve dependencies can be avoided. In our project that makes sense due to we have no real perl program running

Due to we are sure about the MacOSX version, I tollerate build failures under osx

I added a litte bash function to avoid redundancy during testing

… the test_fasta function

…CIAL_FLAG

… test

…nd moved input file definition down to tests

…rational test

…ational test

…sed, due to it seems to be broken

…izing it

Changed the way, the combined output will be generated. So each test will
generate its own set of output files. The name of the output files are generated
according to:

	  tmp.TESTNUMBER.*

So the tests if the correct output was generated can now avoid diff, but use the
md5sum of the output instead.

… approach

This is expected to fail for the original test script, but should work on the new one

To generate the sums based on the original one, I used the following perl statement:

```
perl -ne '

     unless (/tmp/) { print; next }

     print;

     foreach my $fact (map {$_*14} (1..3))
     {
	$bla=$_;
	$bla=~s/(?<=\.)(\d+)(?=\.)/$1+$fact/eg; print $bla;
     }

' reference.md5
```

Testing at Travis-CI is now available