func (s *EnvironmentCommandSuite) TestWriteAddsNewline(c *C) {
	err := cmd.WriteCurrentEnvironment("fubar")
	c.Assert(err, IsNil)
	current, err := ioutil.ReadFile(cmd.GetCurrentEnvironmentFilePath())
	c.Assert(err, IsNil)
	c.Assert(string(current), Equals, "fubar\n")
}
func (*EnvironmentCommandSuite) TestErrorWritingFile(c *C) {
	// Can't write a file over a directory.
	os.MkdirAll(cmd.GetCurrentEnvironmentFilePath(), 0777)
	err := cmd.WriteCurrentEnvironment("fubar")
	c.Assert(err, ErrorMatches, "unable to write to the environment file: .*")
}