Update Docker image

Author: allanrenucci

.drone.yml

@@ -3,35 +3,35 @@ pipeline:
   # We run tests in parallel. Tests run in a copy of the working directory to avoid conflict
   test_legacy:
     group: test
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - cp -R . /tmp/0/ && cd /tmp/0/
       - ./project/scripts/sbt legacyTests
 
   test:
     group: test
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - cp -R . /tmp/1/ && cd /tmp/1/
       - ./project/scripts/sbt test
 
   test_bootstrapped:
     group: test
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - cp -R . /tmp/2/ && cd /tmp/2/
       - ./project/scripts/sbt dotty-bootstrapped/test
 
   test_optimised:
     group: test
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - cp -R . /tmp/3/ && cd /tmp/3/
       - ./project/scripts/sbt ";set bootstrapOptimised in ThisBuild := true ;dotty-bootstrapped/test"
 
   test_sbt:
     group: test
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - cp -R . /tmp/4/ && cd /tmp/4/
       - ./project/scripts/sbt sbt-dotty/scripted
@@ -41,7 +41,7 @@ pipeline:
 
   # DOCUMENTATION:
   documentation:
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     commands:
       - ./project/scripts/genDocs
     secrets: [ bot_pass ]
@@ -51,7 +51,7 @@ pipeline:
   # PUBLISHING:
   # Publishing expect NIGHTLYBUILD or RELEASEBUILD to be set. See dottyVersion in Build.scala
   publish_nightly:
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     environment:
       - NIGHTLYBUILD=yes
     commands:
@@ -64,7 +64,7 @@ pipeline:
       environment: nightly
 
   publish_release:
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     environment:
       - RELEASEBUILD=yes
     commands:
@@ -77,7 +77,7 @@ pipeline:
       environment: release
 
   publish_sbt_release:
-    image: lampepfl/dotty:2017-09-05
+    image: lampepfl/dotty:2017-09-08
     environment:
       - RELEASEBUILD=yes
     commands: