Removed drone images

See .drone.yml and https://hub.docker.com/r/torchbox/scss-lint/

.drone.yml

@@ -1,5 +1,3 @@
-# The scripts for building the base images can be found in scripts/drone-images
-
 pipeline:
   flake8:
     image: python:3.5

scripts/drone-images/flake8/Dockerfile

@@ -1,3 +0,0 @@
-FROM python:3.4
-
-RUN pip3.4 install flake8

scripts/drone-images/jscs/Dockerfile

@@ -1,3 +0,0 @@
-FROM node:4.2.4
-
-RUN npm install -g jscs@"^1.12.0

scripts/drone-images/readme.md

@@ -1,15 +0,0 @@
-Wagtail CI base images
-======================
-
-This directory contains Dockerfiles for building the base images used by
-Wagtail's continuous integration server.
-
-
-Building
---------
-
-Run the following commands to build all the images:
-
-    docker build -t wagtail-flake8 flake8
-    docker build -t wagtail-jscs jscs
-    docker build -t wagtail-scss-lint scss-lint

scripts/drone-images/scss-lint/Dockerfile

@@ -1,8 +0,0 @@
-FROM ruby:2.2
-
-ADD gen_locale.sh /gen_locale.sh
-RUN bash /gen_locale.sh
-ENV LANG=en_GB.UTF-8
-
-# Install scss-lint
-RUN gem install scss-lint

scripts/drone-images/scss-lint/gen_locale.sh

@@ -1,7 +0,0 @@
-apt-get update \
-    && apt-get install -y locales \
-    && rm -rf /var/lib/apt/lists/* \
-
-echo "en_GB.UTF-8 UTF-8" >> /etc/locale.gen
-
-locale-gen