Added configuration file for travis-ci.

Also adapted runalltests script (saves an empty file called failed iff
one of the unit tests fails).

.travis.yml

+language: python
+
+install:
+  - export
+  - sudo add-apt-repository ppa:octave/stable -y
+  - sudo apt-get update -qq
+  - sudo apt-get install -qq octave liboctave-dev
+
+script:
+  - make check-octave
+  - ./success.sh

success.sh

+#!/bin/sh
+if [ -f ./tests/failed ]
+then
+   exit 1
+fi

tests/runalltests.m

 opath = path();
 
-% Check that the m-unit-tests module is available.
+system('rm -f failed');
 
+% Check that the m-unit-tests module is available.
 install_unit_test_toolbox = false;
 
 try
     initialize_unit_tests_toolbox;
 catch
     urlwrite('https://github.com/DynareTeam/m-unit-tests/archive/master.zip','master.zip');
-    warning('off','MATLAB:MKDIR:DirectoryExists')
-    mkdir('../externals')
-    warning('on','MATLAB:MKDIR:DirectoryExists')
-    unzip('master.zip','../externals')
-    delete('master.zip')
-    addpath([pwd() '/../externals/m-unit-tests-master/src'])
+    warning('off','MATLAB:MKDIR:DirectoryExists');
+    mkdir('../externals');
+    warning('on','MATLAB:MKDIR:DirectoryExists');
+    unzip('master.zip','../externals');
+    delete('master.zip');
+    addpath([pwd() '/../externals/m-unit-tests-master/src']);
     initialize_unit_tests_toolbox;
     install_unit_test_toolbox = true;
 end
@@ -28,12 +29,12 @@ catch
 end
 
 if isoctave
-    more off
+    more off;
 end
 
 tmp = dates_src_root;
 tmp = tmp(1:end-1); % Remove trailing slash.
-run_unitary_tests_in_directory(tmp);
+report = run_unitary_tests_in_directory(tmp);
 
 delete('*.log');
 
@@ -41,3 +42,7 @@ if install_unit_test_toolbox
     rmdir('../externals/m-unit-tests-master','s');
 end
 path(opath);
+
+if any(~[report{:,3}])
+    system('touch failed');
+end
\ No newline at end of file