docs(vignette): remove the use of dplyr in the 'mcmc' vignette (and in the 'Suggests' list of the DESCRIPTION file)

- vignettes :
  - param_optim
  - param_mcmc
- RunModel outputs: return only Qsim
Reviewed-by: @francois.bourgin
Refs #101

InputsCrit$Qobs -> InputsCrit$Obs
Refs #52

- Fix issue with chunk 3 of V02.2_param_mcmc
- skip temporarily V02.1_param_optim due to bug in package hydroPSO
- add skip_on_cran() to vignette tests
- reset local variables before each vignette execution
Refs #52

v1.0.13.17 CLEAN: coda::as.mcmc changed into coda::as.mcmc.list in mcmc vignette to avoid error during CRAN check on debian os