[utils] split Projections under the hood
[utils] undo split of Projection
[utils] rename to avoid confusion in deflation
[utils] Arnoldi invariance tolerance
[linsys] set iter to 0
[recycling] add skeleton for recycling solver
[recycling] add recycling CG, MINRES and GMRES
[deflation] remove obsolete files
[recycling] fix bug in initial guess
[recycling] get_ritz()
[setup] add requirements
[docs] add requirements.txt
[setup] try disabling requires
[docs] mock scipy
[docs] more scipy mock
[docs] even moar scipy submodule mocking
[docs] default theme
[utils] allow zero-dim spaces in projection
[utils] Fix projections
[deflation] add Arnoldifyer