migration to material-ui-pickers 2.x

[vascofg]

Won't be able to merge this until react-admin updates to @material-ui/core 3.2.0 or above, because of this:
mui/material-ui-pickers@8b35d65

This is the module that must be updated: https://github.com/marmelab/react-admin/blob/master/packages/ra-ui-materialui/package.json

[sonoy]

Oops. I got this error after I tried to open the picker.

TypeError: _this.props.utils.startOfMonth is not a function
in Calendar (created by Context.Consumer) 
in WithUtils(Calendar) (created by WithStyles(WithUtils(Calendar))) 
in WithStyles(WithUtils(Calendar)) (created by DateTimePicker) 
in div (created by DateTimePickerView$2) 
in DateTimePickerView$2 (created by DateTimePicker) 
in div (created by DateTimePicker) 
in DateTimePicker (created by Context.Consumer) 
in WithUtils(DateTimePicker) (created by BasePicker)
...

---

Updated:

Solved by modifed the package.json

"dependencies": {
    "@date-io/date-fns": "^1.0.1",
    "date-fns": "2.0.0-alpha.25",
    "material-ui-pickers": "^2.1.1"
  }

Also, please keep these lines:

onChange: function onChange(date) {
                return _this2.onChange(date);
              }