Travis CI: also try building w/ libedit

.travis.yml

@@ -7,6 +7,9 @@ notifications:
 env:
  global:
   - secure: "NB5gz8zMejijB1I4agUjAzYnc4lmxTk6ZGy6tc20zPhyCYXtnHFNvS0TYbpD6k1lF8mvDs0V9U+XPEFOxZf+4UOwZJfNsz/AuDAvP48cfeidNvFcZzOQ6rG60MJJ4oyy1KuemKTzZYI5r46+KBjrCa6Ne9HeAKFd4ze2f4H1nyU="
+ matrix:
+  - readline=ON libedit=OFF
+  - readline=OFF libedit=ON
 addons:
  coverity_scan:
   project:
@@ -20,13 +23,16 @@ compiler:
  - clang
  - gcc
 before_install:
+ # We need this PPA for a recent version of libedit
+ - sudo add-apt-repository ppa:ondrej/php -y
  - sudo apt-get update -qq
 install:
- - sudo apt-get install -y help2man
+ - sudo apt-get install -y help2man libedit-dev
 before_script:
  - mkdir build
  - cd build
 script:
- - cmake .. -DCMAKE_INSTALL_PREFIX=/usr
+ - cmake .. -DCMAKE_INSTALL_PREFIX=/usr \
+   -DWANT_READLINE=$readline -DWANT_LIBEDIT=$libedit
  - make
  - cpack -G DEB