v0.3.2

CovarianceFunctions v0.3.2

Diff since v0.3.1

• gramian now automatically recognizes non-symmetric Toeplitz structure
• gramian falls back to the lazy implementation if input kernel k has GenericInput type.

Merged pull requests:

• Adding gradient kernel scalability plot to README (#16) (@SebastianAment)
• added gradient kernel accuracy comparison to README (#17) (@SebastianAment)