bump chrono to 0.4.2

Konstantin Gukov · Konstantin Gukov · commit ddddb8cb5e8f · 2018-05-01T22:53:04.000+05:00
new version has nanoseconds parsing support
diff --git a/Cargo.toml b/Cargo.toml
@@ -5,7 +5,7 @@ version = "1.0.0"
 
 [dependencies]
 pyo3 = "0.2.6"
-chrono = "0.4"
+chrono = "0.4.2"
 
 [lib]
 name = "dtparse"
