MySQL: read parameter 'path' in the YAML config
MySQL: config parameter 'path' is optional
Issue #317 `replace` does not use `Primary` keys

Expand composite primary keys in raw sql.
Factored out common code to generate 'where' stmt from key.

Also, fixed test failing for MySQL.
Better default path for MySQL
Version bump
Fixed PG unittests

Also bumped postgresql-simple requirement to match the one in persistent-postgresql
Merge pull request #318 from lbolla/issue-317

Issue #317 `replace` does not use `Primary` keys
version bump for replace fix
improve Docker build

* ignore everything in the repo
* use zsol haskell image
  * note that ghc 7.6 is not installed now
* compress RUN statements
more docker fixes
fix MongoDB install
add missing type signature
add insertEntityMany to PersistStore
use new generateKey function
use a counter instead of a random number generator
respect seconday unique key
Merge pull request #320 from yesodweb/insertEntityMany

add InsertEntityMany to PersistStore
use an ADT instead of BackendSpecificUpdate
add eachOp for $each