Move to ubuntu:bionic env. of travis

rust compiler isn't a part of the xenial and is needed to building cryptopgraphy wheel
release-engineering · Feb 9, 2021 · cd2c1ef · cd2c1ef
1 parent ec61ceb
commit cd2c1ef
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -1,3 +1,4 @@
+dist: bionic
 sudo: false
 language: python
 before_install: