check_license: Convert to script.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>

.github/travis/check_license.sh

diff --git a/.github/travis/check_license.sh b/.github/travis/check_license.sh
index f917a18..192849a 100755
--- a/.github/travis/check_license.sh
+++ b/.github/travis/check_license.sh
@@ -8,6 +8,8 @@
 #
 # SPDX-License-Identifier:	ISC
 
+set -e
+
 echo
 echo "==========================="
 echo "Check SPDX identifier"
@@ -34,7 +36,7 @@
     for file in $ERROR_FILES; do
         echo "ERROR: $file does not have license information."
     done
-    return 1
+    exit 1
 fi
 
 echo
@@ -66,5 +68,5 @@
     for dir in $ERROR_NO_LICENSE; do
         echo "ERROR: $dir does not have the LICENSE file."
     done
-    return 1
+    exit 1
 fi

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index c9d1b5e..278aff6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,7 +7,7 @@
 
 install:
   - source prepareenv.sh
-  - source .github/travis/check_license.sh
+  - ./.github/travis/check_license.sh
   - source .github/travis/check_python_script.sh
 
 script: