Merge branch 'master' into 'master'

Exposed project directory and project id to the build environment

Exposing the project directory and ID will help with automating Docker integration, for example, mapping a directory in a Docker to the build directory, etc.

See merge request !5

lib/build.rb

@@ -144,6 +144,9 @@ module GitlabCi
       @process.environment['CI_BUILD_ID'] = @id
       @process.environment['CI_BUILD_REPO'] = @repo_url
+      @process.environment['CI_PROJECT_ID'] = @project_id
+      @process.environment['CI_PROJECT_DIR'] = project_dir
+
       @process.start
       @tmp_file_path = @tmp_file.path