java.lang.NoClassDefFoundError: javax/el/ELManager

Downgrade hibernate-validator to version 5 and it will work fine with Tomcat 7. In my case I add next dependency to my pom:

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>5.4.3.Final</version>
</dependency>

Or you can add newer el-api.jat to tomcat lib folder.

You miss the javax.el-api as dependency. Add:

<dependency>
    <groupId>javax.el</groupId>
    <artifactId>javax.el-api</artifactId>
    <version>3.0.0</version>
</dependency>

to your pom.xml