Update drone with custom image

Author: jvican

.drone.yml

@@ -1,10 +1,9 @@
 pipeline:
   build:
-    image: ruby:2.0
+    image: scalaplatform/jdk8-ruby2-coursier:0.1
+    pull: true
     commands:
-      - curl -L -o coursier https://git.io/vgvpD
       - bundle install
-      - chmod +x coursier
       - ./scripts/run-tut.sh
       - rm -r tut-tmp
       - bundle exec jekyll build

.drone.yml.sig

@@ -1 +1 @@
-eyJhbGciOiJIUzI1NiJ9.cGlwZWxpbmU6CiAgYnVpbGQ6CiAgICBpbWFnZTogcnVieToyLjAKICAgIGNvbW1hbmRzOgogICAgICAtIGN1cmwgLUwgLW8gY291cnNpZXIgaHR0cHM6Ly9naXQuaW8vdmd2cEQKICAgICAgLSBidW5kbGUgaW5zdGFsbAogICAgICAtIGNobW9kICt4IGNvdXJzaWVyCiAgICAgIC0gLi9zY3JpcHRzL3J1bi10dXQuc2gKICAgICAgLSBybSAtciB0dXQtdG1wCiAgICAgIC0gYnVuZGxlIGV4ZWMgamVreWxsIGJ1aWxkCg.vnXkcZj1-bb1RTubdu4TQ4uMvp24fwKTPwrBUkxvEys
+eyJhbGciOiJIUzI1NiJ9.cGlwZWxpbmU6CiAgYnVpbGQ6CiAgICBpbWFnZTogc2NhbGFwbGF0Zm9ybS9qZGs4LXJ1YnkyLWNvdXJzaWVyOjAuMQogICAgcHVsbDogdHJ1ZQogICAgY29tbWFuZHM6CiAgICAgIC0gYnVuZGxlIGluc3RhbGwKICAgICAgLSAuL3NjcmlwdHMvcnVuLXR1dC5zaAogICAgICAtIHJtIC1yIHR1dC10bXAKICAgICAgLSBidW5kbGUgZXhlYyBqZWt5bGwgYnVpbGQK.uCV-tIDp9xbL2u2y27B9id6SL89dBfiiiTvVXYxHAbw

scripts/run-tut.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 
-COURSIER_CLASSPATH="$(./coursier fetch -p com.chuusai:shapeless_2.11:2.3.1 org.scala-lang.modules::scala-xml:1.0.3)"
+COURSIER_CLASSPATH="$(coursier fetch -p com.chuusai:shapeless_2.11:2.3.1 org.scala-lang.modules::scala-xml:1.0.3)"
 
-./coursier launch -r "https://dl.bintray.com/tpolecat/maven/" org.tpolecat:tut-core_2.11:0.4.4 -- . tut-tmp '.*\.md$' -classpath "$COURSIER_CLASSPATH" -Xfatal-warnings -feature
+coursier launch -r "https://dl.bintray.com/tpolecat/maven/" org.tpolecat:tut-core_2.11:0.4.4 -- . tut-tmp '.*\.md$' -classpath "$COURSIER_CLASSPATH" -Xfatal-warnings -feature