Remove the direct postgres dependency

This isn't needed.

Author: sfackler

Cargo.toml

@@ -9,7 +9,6 @@ documentation = "https://sfackler.github.io/rust-postgres-range/doc/v0.9.0/postg
 
 [dependencies]
 time = "0.1"
-postgres = "0.15"
 postgres-protocol = "0.3"
 chrono = "0.4.0"
 postgres-shared = { version = "0.4.0", features = ["with-chrono"] }

src/impls.rs

@@ -1,5 +1,5 @@
 use std::error::Error;
-use postgres::types::{FromSql, IsNull, Kind, ToSql, Type};
+use postgres_shared::types::{FromSql, IsNull, Kind, ToSql, Type};
 use postgres_protocol::{self as protocol, types};
 
 use {BoundSided, BoundType, Normalizable, Range, RangeBound};

src/lib.rs

@@ -1,14 +1,16 @@
 //! Types dealing with ranges of values
 #![doc(html_root_url = "https://sfackler.github.io/rust-postgres-range/doc/v0.8.2")]
 
-#[macro_use(to_sql_checked)]
-extern crate postgres;
 extern crate postgres_protocol;
+#[macro_use(to_sql_checked)]
 extern crate postgres_shared;
 extern crate time;
 extern crate chrono;
-use chrono::{DateTime, TimeZone};
 
+#[cfg(test)]
+extern crate postgres;
+
+use chrono::{DateTime, TimeZone};
 use std::cmp::Ordering;
 use std::fmt;
 use std::i32;
@@ -158,7 +160,7 @@ impl Normalizable for Timespec {
     }
 }
 
-impl<T> Normalizable for DateTime<T> 
+impl<T> Normalizable for DateTime<T>
     where T: TimeZone {
     fn normalize<S>(bound: RangeBound<S, DateTime<T>>) -> RangeBound<S, DateTime<T>>
     where