use builtin runtests more explicitly

Author: scivision

.travis.yml

@@ -1,6 +1,10 @@
-dist: focal
-
 language: matlab
 
+os:
+- linux
+
 matlab:
-  - latest
+- latest
+
+script:
+- matlab -batch "r = runtests('matmap3d.tests'); assert(~isempty(r)); assertSuccess(r)"

README.md

@@ -26,7 +26,7 @@ import matmap3d.*
 Optionally, verify functionality:
 
 ```matlab
-runtests
+runtests('matmap3d.tests')
 ```
 
 ### Functions
@@ -77,3 +77,10 @@ https://www.mathworks.com/matlabcentral/answers/443558-matlab-crashes-when-using
 
 In particular, since PyMap3D uses Astropy for ECI transformations the accuracy will generally be better for eci2* or *2eci functions.
 All other functions should have equivalent accuracy with Matlab vs. Python.
+
+### GNU Octave
+
+GNU Octave users should consider the
+[Octave Mapping Toolbox](https://octave.sourceforge.io/mapping/index.html),
+which added similar functions in
+[version 1.4](http://hg.code.sf.net/p/octave/mapping/file/tip/NEWS).