Remove map() call (#27)
Remove map() call (#27)

Avoid the overhead of constructing the tuple, map object, and deconstructing it:

```
In [1]: from math import radians

In [2]: a = b = c = d = 1.0

In [3]: %timeit ar, br, cr, dr = map(radians, (a, b, c, d))
427 ns ± 1.54 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

In [4]: %timeit ar = radians(a) ; br = radians(b) ; cr = radians(c) ; dr = radians(d)
271 ns ± 1.79 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
```

Whilst a micro-optimization, `haversine()` is often called on large data sets so this can lead to an overall large speedup.
mapado/haversine