Update branch name: master -> development

Based on:
ba68d52aa135fff6d279e1486a70b6a1952fefa7
ef8fc9df939f8875d8c69ef41619c40a1287a352
ae332bf8b1a810ce255ee5207008f564371254ed
in the 1.14 branch.

.travis.yml

@@ -12,22 +12,22 @@ cache:
 matrix:
   include:
     - compiler: gcc
-      env: CXXSTD=14 NLS=true LTS=1604 BRANCH=master
+      env: CXXSTD=14 NLS=true LTS=1604 BRANCH=development
 
     - compiler: gcc
-      env: TOOL=scons CXXSTD=17 NLS=false LTS=1804 BRANCH=master
+      env: TOOL=scons CXXSTD=17 NLS=false LTS=1804 BRANCH=development
 
     - compiler: gcc
-      env: TOOL=scons CXXSTD=14 NLS=false LTS=1604 BRANCH=master OPT=-O0
+      env: TOOL=scons CXXSTD=14 NLS=false LTS=1604 BRANCH=development OPT=-O0
 
     - compiler: gcc
-      env: TOOL=cmake CXXSTD=14 NLS=false LTS=1604 BRANCH=master
+      env: TOOL=cmake CXXSTD=14 NLS=false LTS=1604 BRANCH=development
 
     - compiler: clang
-      env: TOOL=scons CXXSTD=14 NLS=false LTS=1604 BRANCH=master OPT=-O0
+      env: TOOL=scons CXXSTD=14 NLS=false LTS=1604 BRANCH=development OPT=-O0
 
     - compiler: clang
-      env: TOOL=cmake CXXSTD=14 NLS=false LTS=1604 BRANCH=master
+      env: TOOL=cmake CXXSTD=14 NLS=false LTS=1604 BRANCH=development
 
     - os: osx
       compiler: clang

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/wesnoth/wesnoth.svg?branch=master)](https://travis-ci.org/wesnoth/wesnoth)
+[![Build Status](https://travis-ci.org/wesnoth/wesnoth.svg?branch=development)](https://travis-ci.org/wesnoth/wesnoth)
 [![Build status](https://ci.appveyor.com/api/projects/status/nv5jnof3lk3j6kg6?svg=true)](https://ci.appveyor.com/project/wesnoth/wesnoth)
 [![License: GPL v2](https://img.shields.io/badge/License-GPL%20v2-blue.svg)](https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html)
 [![Coverity Scan](https://img.shields.io/coverity/scan/1063.svg)](https://scan.coverity.com/projects/wesnoth)