pycalculix v0.9.5

This version fixes bugs and resolves github issues.
Changes are listed below:

• Adds tests: sample tests at tests/test_samples.py
• Adds tests: meshing tests at tests/test_meshing.py
• Adds solving and meshing timeout exception to capture when they hang
• Fixes dxf import feature, syntax updates to use dfxgrabber >= 0.8.0,
  Issue 32
• Adds requirement for dfxgrabber >= 0.8.0 to ensure that dxf import works
• Pegs Mac gmsh version to gmsh == 3.0.5 because version 3.0.6
  throws segault errors when meshing
• Fixes a bug where solver input file does not write material before
  time steps, Issue 32
• Fixed ccx installer on Windows: zip file is now found and
  downloaded
• Throws an exception if ccx version is too old, v 2.7 and earlier is
  too old
• Pegs Win gmsh install version to 3.0.5
• Updates the calculation for element Seqv, S1, S2, and S3 avg max
  and min values. Now calculates Seqv and principal stresses at all
  integration points, then calculates the avg max and min of those
  values
• Win pegged ccx to version 2.12
• Mac brew brewsci/science/calculix-ccx is currently at ccx version 2.13
• Ubuntu apt-get calculix-ccx is currently is currently at version 2.11