Fix the grdtrack example to avoid crashes on macOS (#531)

* Fix the grdtrack gallery example to avoid crashes
* Enable building documentation

Author: seisman

.github/workflows/ci_tests.yaml

@@ -112,9 +112,9 @@ jobs:
         run: make test PYTEST_EXTRA="-r P"
 
       # Build the documentation
-      #- name: Build the documentation
-      #  shell: bash -l {0}
-      #  run: make -C doc clean all
+      - name: Build the documentation
+        shell: bash -l {0}
+        run: make -C doc clean all
 
       # Upload coverage to Codecov
       - name: Upload coverage to Codecov

examples/gallery/grid/track_sampling.py

@@ -24,7 +24,7 @@
 
 fig = pygmt.Figure()
 # Plot the earth relief grid on Cylindrical Stereographic projection, masking land areas
-fig.basemap(region="g", frame=True, projection="Cyl_stere/150/-20/8i")
+fig.basemap(region="d", frame=True, projection="Cyl_stere/8i")
 fig.grdimage(grid=grid, cmap="gray")
 fig.coast(land="#666666")
 # Plot using circles (c) of 0.15cm, the sampled bathymetry points