DOC: added dev process and updated links
DEV: Chebyshev polynomials
ENH: symmetry of kG and kLL
ENH: symmetry of kG and kLL and improved code format
ENH: symmetry of kG and kLL
BUG: fixed material property
ENH: parameter triu_only to print only upper triangle of a sparse matrix
ENH: symmetry of kG and kLL
ENH: symmetry of k0, k0edges and kG0
ENH: symmetry of k0, k0edges and kG0
ENH: improved code format and removed the non-working prescribed displacement
ENH: symmetry k0, k0edges, kG0
STY: PEP8
DEP: changes already applied
DEP: removed
DEP: non_linear module removed