Split up single_gene_deletion tests
Split up single_gene_deletion tests

Even though it was more elegant the previous test mixed test cases for
the fba and moma single gene deletion. Those cases are now split up into
two distinct test cases to make debugging easier.

jeicher/cobrapy,aebrahim/cobrapy,zakandrewking/cobrapy,zakandrewking/cobrapy,aebrahim/cobrapy,jeicher/cobrapy