use focal with openssl 1.1.1 as the default, add openssl 1.1.0 to the matrix
diff --git a/.travis.yml b/.travis.yml
index 49feef0..eaf8d82 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,19 +4,29 @@
 
 matrix:
   include:
-    - name: Linux (gcc-8)
+    - name: Linux (gcc)
       os: linux
-      compiler: gcc-8
-      addons:
-        apt:
-          sources: ['ubuntu-toolchain-r-test']
-          packages: ['gcc-8']
+      dist: focal
+      compiler: gcc
       before_install: &bs_linux
         - sudo apt-get install faketime libscope-guard-perl libtest-tcp-perl
     - name: Linux (clang)
       os: linux
+      dist: focal
       compiler: clang
       before_install: *bs_linux
+    - name: Linux (OpenSSL 1.1.0)
+      os: linux
+      before_install:
+        - sudo apt-get install faketime libscope-guard-perl libtest-tcp-perl
+        - curl https://www.openssl.org/source/old/1.1.0/openssl-1.1.0l.tar.gz | tar xzf -
+        - cd openssl-1.1.0l
+        - ./config --prefix=/usr/local/openssl-1.1.0
+        - make
+        - sudo make install
+        - cd ..
+      env:
+        - PKG_CONFIG_PATH=/usr/local/openssl-1.1.0/lib/pkgconfig
     - name: Linux (OpenSSL 1.0.2)
       os: linux
       before_install: