ci: Build wheels and publish to wheelhost

This commit introduces a Jenkins pipeline definition and accompanying
shell scripts to build Wheel packages for *taiga-back*. These packages
are then uploaded to the "wheelhost" (i.e *file0.pyrocufflink.blue*,
presently), where they can then be used by `pip` to install Taiga on the
production machine. This makes it possible to install Taiga without
needing build-time dependencies on the final host.

ci/Dockerfile

@@ -0,0 +1,11 @@
+FROM fedora:28
+
+RUN useradd -M -l -u 3000018 jenkins
+RUN dnf install -y \
+	gcc \
+	libjpeg-devel \
+	openssh-clients \
+	python3-devel \
+	rsync \
+	zlib-devel \
+	--

ci/Jenkinsfile

@@ -0,0 +1,34 @@
+pipeline {
+    agent {
+        dockerfile {
+            dir 'ci'
+            args '-v /etc/ssh/ssh_known_hosts:/etc/ssh/ssh_known_hosts:ro'
+        }
+    }
+
+    triggers {
+        pollSCM ''
+    }
+
+    environment {
+        PUBLISH_HOST = 'file0.pyrocufflink.blue'
+        XDG_CACHE_HOME = "${WORKSPACE}"
+    }
+
+    stages {
+        stage('Build') {
+            steps {
+               sh '. ci/build.sh' 
+            }
+        }
+
+        stage('Publish') {
+            steps {
+                sshagent(['jenkins-sftp']) {
+                    sh '. ci/publish.sh'
+                }
+            }
+        }
+    }
+
+}

ci/build.sh

@@ -0,0 +1,8 @@
+rm -rf .venv
+python3.6 -m venv .venv
+
+rm -rf dist
+.venv/bin/pip install --upgrade pip setuptools wheel
+.venv/bin/pip wheel -w dist -r requirements.txt
+
+sed -i '/^-i/d' requirements.txt

ci/publish.sh

@@ -0,0 +1,9 @@
+: ${PUBLISH_PATH:=/var/lib/wheels/taiga}
+
+rsync -rtiO \
+	--delete \
+	--include '*.whl' \
+	--include requirements.txt \
+	dist/ \
+	requirements.txt \
+	${PUBLISH_HOST}:${PUBLISH_PATH%/}/