PARQUET-1607: Remove duplicate maven-enforcer-plugin (#658)
PARQUET-1607: Remove duplicate maven-enforcer-plugin (#658)

* PARQUET-1607: Remove duplicate maven-enforcer-plugin

[WARNING] Some problems were encountered while building the effective model for org.apache.parquet:parquet-cascading3:jar:1.12.0-SNAPSHOT
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-enforcer-plugin @ org.apache.parquet:parquet-cascading3:[unknown-version], /home/travis/build/Fokko/parquet-mr/parquet-cascading3/pom.xml, line 167, column 15
[WARNING]

* Add exclusion for slf4j-log4j12

laurentgo/parquet-mr,laurentgo/parquet-mr,SinghAsDev/parquet-mr,apache/parquet-mr,SinghAsDev/parquet-mr,apache/parquet-mr,laurentgo/parquet-mr,SinghAsDev/parquet-mr,apache/parquet-mr