relax version requirement on HDF5

[bluesquall]

Following the installation instructions for FLOWUnsteady results in an Error:

ERROR: LoadError: Unsatisfiable requirements detected for package GeometricTools [83792f5e]:
 GeometricTools [83792f5e] log:
 ├─possible versions are: 2.1.2 - 2.3.3 or uninstalled
 ├─restricted to versions * by FLOWNoise [d27480ee], leaving only versions: 2.1.2 - 2.3.3
 │ └─FLOWNoise [d27480ee] log:
 │   ├─possible versions are: 2.3.3 or uninstalled
 │   └─FLOWNoise [d27480ee] is fixed to version 2.3.3
 ├─restricted to versions 2.3.0 - 2 by FLOWUnsteady [b491798d], leaving only versions: 2.3.0 - 2.3.3
 │ └─FLOWUnsteady [b491798d] log:
 │   ├─possible versions are: 3.4.0 or uninstalled
 │   └─FLOWUnsteady [b491798d] is fixed to version 3.4.0
 └─restricted by compatibility requirements with HDF5 [f67ccb44] to versions: uninstalled — no versions left
   └─HDF5 [f67ccb44] log:
     ├─possible versions are: 0.9.4 - 0.17.2 or uninstalled
     └─restricted to versions 0.17 by FLOWVPM [6e19019d], leaving only versions: 0.17.0 - 0.17.2
       └─FLOWVPM [6e19019d] log:
         ├─possible versions are: 4.0.1 or uninstalled
         └─FLOWVPM [6e19019d] is fixed to version 4.0.1
Stacktrace:
...

Relaxing the version requirements on the HDF5 package for GeometricTools.jl to allow version 0.17 avoids this error. (And FLOWVPM actually restricts to only version 0.17 of HDF5.)

I'm just getting started with FLOWUnsteady. I can't guarantee this doesn't introduce a different problem downstream.