fix build with feature serial (#5)

setup "script" by hand, to check:
- how tests works with debug build (arithmetic overflow is only
checked in debug release)
- check that documentations builds without errors
- check build with feature = "serial"
- check build of examples

.travis.yml

@@ -9,3 +9,11 @@ matrix:
   allow_failures:
     - rust: nightly
   fast_finish: true
+script:
+  - cargo test --verbose --workspace
+  - cargo test --release --verbose --workspace
+  - cd ublox
+  - cargo build --examples
+  - cargo doc
+  - cargo build --features "serial" --examples
+  - cargo doc --features "serial"

ublox/src/serialport.rs

@@ -165,7 +165,7 @@ impl Device {
     pub fn get_position(&mut self) -> Option<Position> {
         match (&self.navstatus, &self.navpos) {
             (Some(status), Some(pos)) => {
-                if status.itow != pos.itow {
+                if status.itow != pos.get_itow() {
                     None
                 } else if status.flags & 0x1 == 0 {
                     None
@@ -181,7 +181,7 @@ impl Device {
     pub fn get_velocity(&mut self) -> Option<Velocity> {
         match (&self.navstatus, &self.navvel) {
             (Some(status), Some(vel)) => {
-                if status.itow != vel.itow {
+                if status.itow != vel.get_itow() {
                     None
                 } else if status.flags & 0x1 == 0 {
                     None