App has user gardens

+ Created model
+ Migrated new model to db
App has custom plants

  + Created model
  + Migrated new model to db
  + Model has association to garden model
resolve merge conflict in schema file with differing version numbers
Merge pull request #5 from emmagard/add_garden

Add user garden and custom plants model
Merge pull request #6 from emmagard/seeds

changed column name from grow_zone to growing_season in plants table
changed column name in custom_plants