Update version info in package.json and setup.py

package.json

 {
   "name": "geomag-algorithms",
-  "version": "0.8.1",
+  "version": "0.8.4",
   "homepage": "http://geomag.usgs.gov/",
   "repository": "https://github.com/usgs/geomag-algorithms.git",
   "description": "Geomagnetism algorithms.",

setup.py

@@ -2,7 +2,7 @@ from distutils.core import setup
 
 setup(
     name='geomag-algorithms',
-    version='0.8.1',
+    version='0.8.4',
     description='USGS Geomag IO Library',
     url='https://github.com/usgs/geomag-algorithms',
     packages=[