eigenvalues 0.4.0

algorithms to compute eigenvalue/eigenvectors of symmetric matrices
Documentation
## [0.4.0] 08/04/2021

### Changed
* use enum for the davidson correction instead of str (#16)

### Removed
* Travis CI workflow

## [0.3.0] 08/06/2020

### New
* Add Lanczos algorithm (#12)

### Fixed
* Only orthogonalize the new vectors added to the subpace.
* Add Eigendavidson argument documentation.

### Changed
* Renamed struc `Eigendavidson` => `Davidson`.

## [0.2.0] 28-02-2029

## Changed
* Used [modified Gram-Schmidt orthogonalization]https://github.com/felipeZ/eigenvalues/issues/8
* [Reduce scaling of the search space]https://github.com/felipeZ/eigenvalues/issues/10

### Fixed
* Bug in DPR correction.

## [0.1.4]

### Changed

* The Davidson method requires a **SpectrumTarget** `enum` argument.

## [0.1.3] 17-01-2020

### Fixed
* Fixed bug generating the subpsace when the diagonal is not sorted.

### Added
* Allow to compute the lowest or highest eigenvalues of the spectrum.


## [0.1.2] 17-01-2020

### Added
* Generate the orthonormal subspace different from the identity matrix when the diagonal values are not sorted.

## [0.1.1] 16-01-2020

### Changed
* Declared **Clone** a [Super Trait]https://doc.rust-lang.org/reference/items/traits.html#supertraits **Matrixoperations**.

## [0.1.0] 16-01-2020

### Added
* First implementation using `f64`.
* Used [nalgebra]https://github.com/rustsim/nalgebra for the linear algebra operations. 
* Both **GDJ** and **DPR** correction methods working.
* Use a Trait to collect the methods that a matrix representation should have to compute the eigenvalue/eigenvectors.