v1.8.0

This release adds support for sparse matrices. Specifically, sparse matrices stored in compressed-sparse-row (CSR) form. As part of the release, the following additions were made.

• Overloading matmul to accommodate sparse matrix multiplication
• Overloading size to query the dimensional information of a sparse matrix
• Overloading transpose to transpose a sparse matrix
• Overloading operators to support interaction with sparse matrices
• Addition of an LU factorization and solver routine for sparse matrices
• Addition of a preconditioned GMRES solver for sparse matrices
• Conversion routines for dense, diagonal, and banded matrices to sparse format
• Conversion routines from sparse format to dense format
• Overload assignment operator to perform conversions between sparse to dense and dense to sparse formats in a comfortable manner