Always use latest Firefox version and echo it for tests

Don't echo version on Windows, because it hangs Firefox
Also add testing with Firefox Beta (and prior ESR, but commented out for now, since we don't support it and we know it breaks)

.travis.yml

@@ -2,15 +2,22 @@ language: cpp
 compiler:
     - gcc
 env:
-    matrix:
-        - FIREFOXVERSION="36.0.1"
-        - FIREFOXVERSION="31.5.0esr"
+    - FX_PATH_SUFFIX=""
+    - FX_PATH_SUFFIX="-esr"
+    - FX_PATH_SUFFIX="-beta"
+#    - FX_PATH_SUFFIX="-prior-esr"
+matrix:
+    fast_finish: true
+    allow_failures:
+        - env: FX_PATH_SUFFIX="-beta"
+        - env: FX_PATH_SUFFIX="-prior-esr"
 notifications:
     email: false
-before_install:
+install:
+    - wget -r -l1 -np -nd -R "index.html*" "http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/latest${FX_PATH_SUFFIX}/linux-x86_64/en-US/?F=0&P=*.tar.*"
+    - tar -xf firefox-*.tar.*
+before_script:
     - export DISPLAY=:99.0
     - sh -e /etc/init.d/xvfb start
-    - wget http://ftp.mozilla.org/pub/firefox/releases/${FIREFOXVERSION}/linux-x86_64/en-US/firefox-${FIREFOXVERSION}.tar.bz2
-    - tar -xjf firefox-${FIREFOXVERSION}.tar.bz2
 script:
     - test/runtests.sh -x firefox/firefox

test/runtests.sh

@@ -77,6 +77,11 @@ user_pref("extensions.zotero.firstRunGuidance", false);
 user_pref("extensions.zotero.firstRun2", false);
 EOF
 
+
+if [ -z $IS_CYGWIN ]; then
+	echo "`MOZ_NO_REMOTE=1 NO_EM_RESTART=1 \"$FX_EXECUTABLE\" -v`"
+fi
+
 makePath FX_PROFILE "$PROFILE"
 MOZ_NO_REMOTE=1 NO_EM_RESTART=1 "$FX_EXECUTABLE" -profile "$FX_PROFILE" \
     -chrome chrome://zotero-unit/content/runtests.html -test "$TESTS" $FX_ARGS