Declare commons-lang3 dependency explicitly

[valfirst]

To avoid build failures like this one:

Error:  Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.15.0:testCompile (default-testCompile) on project crawler4j-commons: Compilation failure: Compilation failure: 
Error:  /home/runner/work/crawler4j/crawler4j/crawler4j-commons/src/test/java/edu/uci/ics/crawler4j/test/SimpleWebURL.java:[22,40] package org.apache.commons.lang3.builder does not exist
Error:  /home/runner/work/crawler4j/crawler4j/crawler4j-commons/src/test/java/edu/uci/ics/crawler4j/test/SimpleWebURL.java:[23,40] package org.apache.commons.lang3.builder does not exist
Error:  /home/runner/work/crawler4j/crawler4j/crawler4j-commons/src/test/java/edu/uci/ics/crawler4j/test/SimpleWebURL.java:[33,65] cannot find symbol
Error:    symbol:   variable ToStringStyle
Error:    location: class edu.uci.ics.crawler4j.test.SimpleWebURL
Error:  /home/runner/work/crawler4j/crawler4j/crawler4j-commons/src/test/java/edu/uci/ics/crawler4j/test/SimpleWebURL.java:[33,24] cannot find symbol
Error:    symbol:   variable ToStringBuilder
Error:    location: class edu.uci.ics.crawler4j.test.SimpleWebURL