ob-ipython-kernel buffer only works after manually activating comint-mode

Thanks for the great package!

I can only use the ob-ipython-kernel buffer after manually activating `comint-mode`. Does anyone else have this issue? I'm afraid my setup is to blame...

#### System Info :computer:
- OS: gnu/linux
- Emacs: 25.3.1
- Spacemacs: 0.300.0
- Spacemacs branch: develop (rev. d4017b1c)
- Graphic display: t
- Distribution: spacemacs-base
- Editing style: emacs
- Completion: helm
- Layers:
```elisp
(haskell javascript graphviz
(treemacs :location local)
(mine :location local)
spacemacs-editing spacemacs-completion
(spacemacs-modeline :packages
(not fancy-battery symon))
(spacemacs-navigation :packages
(not golden-ratio))
spacemacs-visual spacemacs-org better-defaults helm git syntax-checking
(auto-completion :variables auto-completion-return-key-behavior 'complete auto-completion-tab-key-behavior 'cycle)
(org :variables org-confirm-babel-evaluate nil org-export-with-sub-superscripts nil)
(shell :variables shell-default-shell 'eshell)
(version-control :variables version-control-global-margin t version-control-diff-tool 'git-gutter+)
csv common-lisp emacs-lisp html markdown
(python :variables python-test-runner 'pytest)
yaml docker semantic)
```
- System configuration features: XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS NOTIFY FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11