v0.5.3

Krylov v0.5.3

Diff since v0.5.2

Closed issues:

• minres_qlp performs scalar operations on GPU (#215)

Merged pull requests:

• Update the documentation about GPU support (#216) (@amontoison)
• Update kref! for GPU support (#217) (@amontoison)
• Version 0.5.3 (#218) (@amontoison)