我知道我安装了maven：
$ mvn --version
Apache Maven 3.5.0 (ff8f5e7444045639af65f6095c62210b5713f426; 2017-04-03T15:39:06-04:00)
Maven home: /home/roschler/.sdkman/candidates/maven/current
Java version: 1.8.0_25, vendor: Oracle Corporation
Java home: /usr/java/jdk1.8.0_25/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.13.0-123-generic", arch: "amd64", family: "unix"
我相信我根据工作目录的内容正确安装了maven包装器：
$ ls
LICENSE mvnw mvnw.cmd pom.xml README.md src
然而，当我尝试运行maven包装器时，我收到以下错误：
$ ./mvnw
bash: ./mvnw: /bin/sh^M: bad interpreter: No such file or directory
为什么我会收到此错误以及如何解决？