experiment with travis-ci config (for later testing prepared statements)
pass context instead of runtime to set methods supporting prep.statmnts
do not assume correctly typed object being passed as bind value (with PS)
... use #to_i, #to_s and #to_f param conversions where they make sense
e.g. `Entry.find('1')` should convert the string into an integer using `to_i`
support testing with prepared statements e.g.` rake test_mysql PS=true`
if (prepared statement) bind param column nil/not set assume string type
handle nil column in prepared statements explicitly since we depend on it
- see `ArJdbc::PostgreSQL#table_exists?` (Ruby) implementation passing 
`[nil, value]` bind params
avoid using (JDBC) connection's config writer - method no longer available
start testing with PS=true (on travis-ci)
update appraisals - most importantly roll with `gem 'activerecord' ~> 4.0.0`
update adapter jar