Write config.yml

This change updates the buildpack to write a skeleton config.yml with its name
and version number.  This should enable querying against the V3 droplet API to
determine what version of the buildpack was used to build a droplet.

[resolves #812]

Signed-off-by: Ben Hale <[email protected]>

Author: nebhale

.idea/codeStyles/Project.xml

@@ -24,4 +24,4 @@ require 'java_buildpack/buildpack'
 
 app_dir = ARGV[0]
 
-JavaBuildpack::Buildpack.with_buildpack(app_dir, 'Compile failed with exception %s', &:compile)
+JavaBuildpack::Buildpack.with_buildpack(app_dir, nil, nil, 'Compile failed with exception %s', &:compile)