Add Vagrantfile

This defines Linux, FreeBSD and OpenBSD VMs and creates a Go
environment.

Micro-tutorial:

    $ vagrant up freebsd
    [wait...]

    $ vagrant ssh freebsd -c 'cd restic/restic; go test -v ./...'
    [test output]

.gitignore

@@ -5,3 +5,4 @@
 cmd/dirdiff/dirdiff
 cmd/gentestdata/gentestdata
 cmd/restic/restic
+/.vagrant

Vagrantfile

@@ -0,0 +1,99 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+GO_VERSION = '1.4.2'
+
+def packages_freebsd
+  return <<-EOF
+    pkg install -y git
+    pkg install -y curl
+  EOF
+end
+
+def packages_openbsd
+  return <<-EOF
+    . ~/.profile
+    pkg_add git curl bash gtar--
+    ln -sf /usr/local/bin/gtar /usr/local/bin/tar
+  EOF
+end
+
+def packages_linux
+  return <<-EOF
+    apt-get update
+    apt-get install -y git curl
+  EOF
+end
+
+def install_gimme
+  return <<-EOF
+    rm -rf /opt/gimme
+    git clone https://github.com/meatballhat/gimme /opt/gimme
+    perl -p -i -e 's,/bin/bash,/usr/bin/env bash,' /opt/gimme/gimme
+    ln -sf /opt/gimme/gimme /usr/bin/gimme
+  EOF
+end
+
+def prepare_user(boxname)
+  return <<-EOF
+    mkdir -p ~/go/src
+    export PATH=/usr/local/bin:$PATH
+
+    gimme #{GO_VERSION} >> ~/.profile
+    echo export 'GOPATH=$HOME/go' >> ~/.profile
+    echo export 'CDPATH=.:$GOPATH/src/github.com' >> ~/.profile
+    echo export 'PATH=$GOPATH/bin:/usr/local/bin:$PATH' >> ~/.profile
+
+    . ~/.profile
+
+    go get golang.org/x/tools/cmd/cover
+    go get github.com/tools/godep
+
+    echo
+    echo "Run:"
+    echo "  vagrant rsync #{boxname}"
+    echo "  vagrant ssh #{boxname} -c 'cd project/path; godep go test ./...'"
+  EOF
+end
+
+def fix_perms
+  return <<-EOF
+    chown -R vagrant:vagrant /home/vagrant/go
+  EOF
+end
+
+# All Vagrant configuration is done below. The "2" in Vagrant.configure
+# configures the configuration version (we support older styles for
+# backwards compatibility). Please don't change it unless you know what
+# you're doing.
+Vagrant.configure(2) do |config|
+  # disable default mount
+  config.vm.synced_folder ".", "/vagrant", :disabled => true
+
+  # use rsync to copy content to the folder
+  config.vm.synced_folder ".", "/home/vagrant/go/src/github.com/restic/restic", :type => "rsync"
+
+  # fix permissions on synced folder
+  config.vm.provision "fix perms", :type => :shell, :inline => fix_perms
+
+  config.vm.define "linux" do |b|
+    b.vm.box = "ubuntu/trusty64"
+    b.vm.provision "packages linux", :type => :shell, :inline => packages_linux
+    b.vm.provision "install gimme",  :type => :shell, :inline => install_gimme
+    b.vm.provision "prepare user",   :type => :shell, :privileged => false, :inline => prepare_user("linux")
+  end
+
+  config.vm.define "freebsd" do |b|
+    b.vm.box = "geoffgarside/freebsd-10.1"
+    b.vm.provision "packages freebsd", :type => :shell, :inline => packages_freebsd
+    b.vm.provision "install gimme",  :type => :shell, :inline => install_gimme
+    b.vm.provision "prepare user",   :type => :shell, :privileged => false, :inline => prepare_user("freebsd")
+  end
+
+  config.vm.define "openbsd" do |b|
+    b.vm.box = "tmatilai/openbsd-5.6"
+    b.vm.provision "packages openbsd", :type => :shell, :inline => packages_openbsd
+    b.vm.provision "install gimme",  :type => :shell, :inline => install_gimme
+    b.vm.provision "prepare user",   :type => :shell, :privileged => false, :inline => prepare_user("openbsd")
+  end
+end