Delete blas.Order from testing code

After discussion on the gonum-dev mailing list, it was decided to remove
support for blas.Order and only deal with row major matrices.

This PR removes blas.Order code from the testblas package. The other packages
will follow in subsequent commits
Delete blas.Order from testing code

This PR removes blas.Order code from the testblas package. The other packages
will follow next
Remove order type from base Blas package.

After discussion on gonum-dev, it was decided to remove the Order type
from the Blas package and make all operations on RowMajor matrices.
This commit removes the order type from blas. Removal from the remaining
packages will happen in following commits
Remove blas from blas/goblas

This is the third is a series of commits for removing column major support from blas.
This commit removes such support from the goblas package
Merge branch 'master' of https://github.com/btracey/blas

Conflicts:
	testblas/dgemm.go
	testblas/dgemv.go
	testblas/dtrsm.go