Revert "Use drone.io instead of Travis"

This reverts commit 8e699f8.

.travis.yml

@@ -0,0 +1,18 @@
+language: go
+
+go:
+   - tip
+
+install:
+   - export PATH=$PATH:$HOME/gopath/bin
+   - ./build.sh setup
+
+script:
+   - ./build.sh test-cov
+
+after_success:
+   - goveralls -coverprofile=coverage.out -service=travis-ci -package=calmh/syncthing -repotoken="$COVERALS_TOKEN"
+
+env:
+   global:
+      secure: "zEV2h2XtKHNLVdXJjM4LA/VjMfLVydm6goF+ARit+nOSGxGoH7f7jIdzJzhxgh7shKG93q61eLO1Tug+WBMYB2EpBuYnTB5AIMYhCDwNI8C4uBV6c3brHfcrie7MASNao8TID2QScASKNFFWvjv/i1Ccn5ztxdcQuhSsNjGZp8A="

README.md

@@ -1,8 +1,8 @@
 syncthing
 =========
 
-Build status: [![Build Status](https://drone.io/github.com/calmh/syncthing/status.png)](https://drone.io/github.com/calmh/syncthing/latest)
-Coverage status: [![Coverage Status](https://img.shields.io/coveralls/calmh/syncthing.svg)](https://coveralls.io/r/calmh/syncthing?branch=master)
+[![Build Status](https://img.shields.io/travis/calmh/syncthing.svg?style=flat)](https://travis-ci.org/calmh/syncthing)
+[![Coverage Status](https://img.shields.io/coveralls/calmh/syncthing.svg?style=flat)](https://coveralls.io/r/calmh/syncthing?branch=master)
 
 This is the `syncthing` project. The following are the project goals: