Cannot create user or login

Hello,

In order to have a generic setup for my grav projects, I tried to create a bootstrap procedure, but I'm stuck with the admin plugin.

The aim is the following : Installing grav from git in order to being able to use git pull for upgrades and pushing my project on any git(hub/lab/olite) host, and deploying easily. All of this should be automated using ansible or any shell script.

Before trying to deploy online on a linux machine, I tried to bootstrap it manually on my Mac OSX 10.12.2... and failed.

I use an hombrew-ed nginx, with php 7.0 fpm. I used to use grav and my other (manually installed) existing grav projects works flawlessly with this osx setup.

Here is the steps I followed :

- cloning grav develop branch `git clone https://github.com/getgrav/grav.git myproject`
- entering myproject `cd myproject`
- installing grav `bin/grav install`
- installing admin plugin `bin/gpm install admin`

Everything seems to be installed perfectly (“*Grav is running!*”)
Before going further, I verify the Admin plugin by opening the corresponding url `http://myproject.dev/admin` (dnsmasq is resolving my .dev projects locally)

The Admin plugin detects no user account and provides me the usual form in order to create the very first user.
I fill in the form, being carefully respecting the validation rules, but I'm always redirected to the same empty form with the following error message :
`Oops there was a problem, please check your input and submit the form again.`

I tried with a CLI user creation but the result is the same.

I also tried with the manual user creation but I cannot log-in : I always get a `Invalid security token` error (and my password is not hashed and remains clear)

I thought it was a permission issue, but comparing the existing project permissions with the fresh one did not show me anything special, so in order to be sure, I tried to `chmod -R a+w .` and did not notice any better changes.

What did I miss ? Could you help me to figure out where is my mistake, please ?