Issue GridapGmsh in Windows 10

[c-schubert]

Query of deps/build.jl line 20 and 21 does not work under Windows 10, even if the environment variable to the GMSH SDK is set correctly.

 gmsh_bin = joinpath(gmsh_root,"bin","gmsh")
  if isfile(gmsh_bin)

Fix is:

 gmsh_bin = joinpath(gmsh_root,"bin","gmsh.exe")
  if isfile(gmsh_bin)

Of course, a query of the target system should be made before ,so that at the same the functionality for Unix systems is not disturbed ...

[fverdugo]

Thanks for reporting! Perhaps we can check that either gmsh or gmesh.exe exists. Can you open a PR?

[c-schubert]

Done but found another issue, I do not know how to fix in a hurry ... , will open another issue in this #38 ...

[fverdugo]

Fixed in PR #37