Add license and script checking that CLA has been signed (#14)

Add script checking that contributors have signed the Scala CLA
Add BSD-3-Clause license file

Author: julienrf

.travis.yml

@@ -5,6 +5,8 @@
 #      - oracle-java8-installer
 language: scala
 jdk:
-- oraclejdk8
+  - oraclejdk8
+before_script:
+  - ./checkCLA.sh
 script:
-- sbt +test
+  - sbt +test

LICENSE

@@ -0,0 +1,28 @@
+Copyright (c) 2002-2018 EPFL
+Copyright (c) 2011-2018 Lightbend, Inc.
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+  * Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+  * Neither the name of the EPFL nor the names of its contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

checkCLA.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Script copied from https://github.com/scalameta/scalameta
+set -e
+
+if [ "$TRAVIS_PULL_REQUEST" != "false" ] ; then
+  echo "Incoming pull request from https://github.com/$TRAVIS_REPO_SLUG/pull/$TRAVIS_PULL_REQUEST";
+  author=$(curl -u dummy4dummy:dummy2dummy -s "https://api.github.com/repos/$TRAVIS_REPO_SLUG/pulls/$TRAVIS_PULL_REQUEST" | jq -r ".user.login");
+  if [ $? -ne 0 ] ; then exit 1; fi;
+  echo "Pull request submitted by $author";
+  signed=$(curl -s https://www.lightbend.com/contribute/cla/scala/check/$author | jq -r ".signed");
+  if [ $? -ne 0 ] ; then exit 1; fi;
+  if [ "$signed" = "true" ] ; then
+    echo "CLA check for $author successful";
+  else
+    echo "CLA check for $author failed";
+    echo "Please sign the Scala CLA to contribute to $TRAVIS_REPO_SLUG";
+    echo "Go to https://www.lightbend.com/contribute/cla/scala and then resubmit this pull request";
+    exit 1;
+  fi;
+fi;