version changed to 3, circle ci to use ghc 7.10.1, stricter import/export in PgQuery and remove of dead code

postgrest.cabal

@@ -2,7 +2,7 @@ name:                  postgrest
 description:           Reads the schema of a PostgreSQL database and creates RESTful routes
                        for the tables and views, supporting all HTTP verbs that security
                        permits.
-version:               0.2.11.1
+version:               0.3.0.0
 synopsis:              REST API for any Postgres database
 license:               MIT
 license-file:          LICENSE
@@ -22,6 +22,11 @@ Flag CI
   Default:     False
 
 executable postgrest
+  if flag(ci)
+    ghc-options:       -Wall -W -Werror
+  else
+    ghc-options:       -Wall -W -O2
+
   main-is:             PostgREST/Main.hs
   default-extensions:  OverloadedStrings, ScopedTypeVariables, QuasiQuotes
   default-language:    Haskell2010