Merge pull request #456 from probcomp/20220303-alexlew-travis-fixes

Update Travis config

Author: ztangent

.travis.yml

@@ -1,17 +1,20 @@
 # See http://docs.travis-ci.com/user/languages/julia/ and https://juliadocs.github.io/Documenter.jl/stable/man/hosting/#Hosting-Documentation-1
 # See status of Travis builds at https://travis-ci.org/probcomp/Gen
 
+# As of March 2022, Gen is not compatible with Julia 1.7,
+# due to a regression involving NamedTuples:
+# https://github.com/JuliaLang/julia/issues/43783
+# The fix is already in `nightly` and slated for 1.8;
+# hopefully it will also be backported 
+# to a future minor release of 1.7.
 language: julia
 julia:
-  - 1.4
-  - 1.5
-  - 1.6
+  - 1.3 # earliest supported version
+  - 1.6 # LTS
+  - nightly
 
 jobs:
   include:
-    - stage: test
-      script:
-        - julia -e 'using Pkg; Pkg.build(); Pkg.test()'
     - stage: docs
       julia: 1.6
       os: linux