travis: split "torture" into a separate "events" build as well

Run torture without FTP and reducing coverage to 20%

For some reason the torture tests now run a lot slower on travis and run
into the 50 minute limit all the time.

Closes #6728

.travis.yml

@@ -298,6 +298,19 @@ jobs:
         - libbrotli-dev
         - libzstd-dev
         - libssh2-1-dev
+  - env:
+    - T=events
+    - OVERRIDE_CC="CC=gcc-8" OVERRIDE_CXX="CXX=g++-8"
+    addons:
+      apt:
+        <<: *common_apt
+        packages:
+        - *common_packages
+        - lcov
+        - libpsl-dev
+        - libbrotli-dev
+        - libzstd-dev
+        - libssh2-1-dev
   - env:
     - T=distcheck
     - OVERRIDE_CC="CC=gcc-8" OVERRIDE_CXX="CXX=g++-8"

scripts/travis/script.sh

@@ -36,11 +36,17 @@ if [ "$T" = "coverage" ]; then
 fi
 
 if [ "$T" = "torture" ]; then
+  ./configure --enable-debug --disable-shared --disable-threaded-resolver --enable-code-coverage --enable-werror --with-libssh2
+  make
+  tests="!TLS-SRP !FTP"
+  make "TFLAGS=-n --shallow=20 -t $tests" test-nonflaky
+fi
+
+if [ "$T" = "events" ]; then
   ./configure --enable-debug --disable-shared --disable-threaded-resolver --enable-code-coverage --enable-werror --with-libssh2
   make
   tests="!TLS-SRP"
   make "TFLAGS=-n -e $tests" test-nonflaky
-  make "TFLAGS=-n --shallow=40 -t $tests" test-nonflaky
 fi
 
 if [ "$T" = "debug" ]; then