fix read variable in for loop

[MartinPippel]

• issue:

  • the for loop does always use the full list of given read files in each iteration and creates the same meryl database with different database names

• solution:

  • use read variable name in bash for loop

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[mahesh-panchal]

The other tests are updated but merfin has a habit of seg faulting. It takes some tries to get it through.

[mahesh-panchal]

I made an issue on the merfin repo to see if they'll do an updated package on bioconda, but I'm not expecting anything anytime soon. I don't have the time to update the bioconda recipe.