Travis fix

.travis.yml

@@ -1,16 +1,36 @@
 language: python
+
+dist: bionic
+
+addons:
+  apt:
+    packages:
+      - libpcre2-dev
+
+arch:
+  - arm64
+  - amd64
+    #  - ppc64le
+    #  - s390x
+
 python:
-    - "2.6"
-    - "2.7"
-    - "3.3"
-    - "3.4"
-    - "3.5"
-    - pypy
+    - "3.6"
+    - "3.7"
+    - "3.8"
     - pypy3
+
+# there is no pypy3 for arm64 on Travis CI      
+jobs:
+  exclude:
+    - arch: arm64
+      python: pypy3
+
 install:
     - pip install .
     - pip install pillow pytest-cov coveralls
+
 script:
     py.test --cov scss
+
 after_success:
     coveralls