Add a basic recipe that loads postgis
user
```ruby
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

apt_repository 'ppa_sharpie_for-science' do
  uri 'http://ppa.launchpad.net/sharpie/for-science/ubuntu'
  distribution node['lsb']['codename']
  components ["main"]
  keyserver 'keyserver.ubuntu.com'
  key 'DAF764E2'
  deb_src true
end

apt_repository 'ppa_sharpie_postgis-stable' do
  uri 'http://ppa.launchpad.net/sharpie/postgis-stable/ubuntu'
  distribution node['lsb']['codename']
  components ['main']
  keyserver 'keyserver.ubuntu.com'
  key 'DAF764E2'
  deb_src true
end

apt_repository 'ppa_ubuntugis_ubuntugis-unstable' do
  uri 'http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu'
  distribution node['lsb']['codename']
  components ['main']
  keyserver 'keyserver.ubuntu.com'
  key '314DF160'
  deb_src true
end

package 'python-software-properties'
package 'postgresql-9.1-postgis2'
```
assistant