Allow overriding of server.xml header and footer

At present, there's no straightforward way to change the content of the
server.xml header or footer concat fragment; this patch adds parameters
that accept paths to alternate ERB templates to be evaluated in
`tomcat::config` to generate those fragments.
Add Gemfile.lock to .gitignore
Merge pull request #17 from huit/override_server_fragments

Override server fragments
remove puppet 3.0 from rspec testing - loader bug
Merge pull request #18 from jlambert121/drop_3.0

remove puppet 3.0 from rspec testing - loader bug
tag 0.9.0 release
Merge pull request #19 from jlambert121/v0.9.0

tag 0.9.0 release