Replace Travis with Github Actions (#416)

Closes #415

Also enables coverage tracking of Django templates, hence the ~30% drop in coverage!

PyRIGS/tests/base.py

@@ -24,10 +24,8 @@ def create_browser():
     # No caching, please and thank you
     options.add_argument("--aggressive-cache-discard")
     options.add_argument("--disk-cache-size=0")
-    # God Save The Queen
-    options.add_argument("--lang=en_GB")
     options.add_argument("--headless")
-    if os.environ.get('CI', False):
+    if settings.CI:
         options.add_argument("--no-sandbox")
     driver = webdriver.Chrome(options=options)
     return driver