We cannot use openjdk6 since maven central wont serve TLS1.0

see https://stackoverflow.com/a/50824799/449071

Author: MasseGuillaume

.travis.yml

@@ -12,7 +12,7 @@ scala:
   - 2.12.6
   - 2.13.0-M4
 jdk:
-  - openjdk6
+  - openjdk7
   - oraclejdk8
 env:
   global:
@@ -31,10 +31,10 @@ env:
 matrix:
   exclude:
     # > 2.12 requires jdk8
-    - jdk: openjdk6
+    - jdk: openjdk7
       scala: 2.12.6
 
-    - jdk: openjdk6
+    - jdk: openjdk7
       scala: 2.13.0-M4
 
     # ?
@@ -63,7 +63,7 @@ matrix:
 # |    openjdk6 | 2.11.12   | jvm          |                      |               |
 # |    openjdk6 | 2.11.12   | js           | 0.6.23               |               |
 # |    openjdk6 | 2.11.12   | js           | 1.0.0-M3             |               |
-# |  oraclejdk8 | 2.11.12   | native       | 0.3.7                |               |
+# |    openjdk6 | 2.11.12   | native       | 0.3.7                |               |
 # |  oraclejdk8 | 2.12.6    | jvm          |                      |               |
 # |  oraclejdk8 | 2.12.6    | js           | 0.6.23               |               |
 # |  oraclejdk8 | 2.12.6    | js           | 1.0.0-M3             |               |