Merge pull request #317 from JuliaRobotics/travis/1Q20/jl14

try add julia 1.4 testing

Author: dehann

.travis.yml

@@ -13,21 +13,20 @@ services:
 
 julia:
     - 1.0
-    - 1.2
-    - 1.3
+    - 1.4
     - nightly
 
 env:
     - IIF_TEST=false
 
 jobs:
   include:
-    - julia: 1.2
+    - julia: 1.3
       env: IIF_TEST=true
       if: NOT branch =~ ^release.*$
     - arch: arm64
     - stage: "Documentation"
-      julia: 1.2
+      julia: 1.3
       os: linux
       script:
         - julia --project=docs/ -e 'using Pkg; Pkg.develop(PackageSpec(path=pwd())); Pkg.instantiate()'