1) Create a folder in the root directory of the project
mkdir repo
2) Install dependencies to the repo using the maven command
mvn org.apache.maven.plugins:maven-install-plugin:2.5.1:install-file -Dfile=path-to-your-artifact-jar -DgroupId=your.groupId -DartifactId=your-artifactId -Dversion=version -Dpackaging=jar -DlocalRepositoryPath=path-to-specific-local-repo
3) Be careful to remove .pom and jar from .gitignore
4) git add repo
5) Edit project.clj and add the line
:local-repo "repo"
Leiningen will look for your secret dependencies in repo and in public repositories for all other dependencies.