Update to version 1.3

See merge request !7

- Change tau-params by intuition ¯\_(ツ)_/¯

- Add Galerking Least Squaes Stabilization (GLS) (easy for linear equation)
- Includes addition of div3d3 and gen3d1 in tensoroperations module
- Includes gls keyword in input.yml with 5 parameters
- 3 new test cases added (heat, stress, r13)
- Method works out nicely, especially for R13 case!
- Further studies needed (use better computer for finer meshes)

- To avoid recloning of repo <-> changing SHA of reqirements.txt?
- See GIT_STRATEGY: fetch

- to hopefully get proper cachicng done