remove NaN values in RinexNav

[betaBison]

• Removes NaN rows that georinex outputs when parsing Rinex Nav data files
• Fixes #155

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (c9457b1) 99.56% compared to head (ec70614) 99.56%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## v1.0.2 #156 +/- ## ======================================= Coverage 99.56% 99.56% ======================================= Files 21 21 Lines 2980 2980 ======================================= Hits 2967 2967 Misses 13 13 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.