Use Xenial in Travis CI

Author: Xanewok

.travis.yml

@@ -1,6 +1,5 @@
 language: rust
-dist: trusty
-sudo: false
+dist: xenial
 cache:
   cargo: false
 os:
@@ -14,9 +13,6 @@ install:
   - rustup component add rust-src
   - rustup component add rust-analysis
 script:
-  - cargo build -v
-  - cargo test -v
-  - cargo test test_tooltip_std -- --ignored
   # Since the rls-* subcrates use crates.io-based dependencies of themselves it
   # makes sense to test them in isolation rather than just RLS itself
   - (cd rls-analysis && cargo test -v)
@@ -25,6 +21,9 @@ script:
   - (cd rls-rustc && cargo test -v)
   - (cd rls-span && cargo test -v)
   - (cd rls-vfs && cargo test -v)
+  - cargo build -v
+  - cargo test -v
+  - cargo test test_tooltip_std -- --ignored
 
 env:
   global: