Remove mention of gitter.im (#405)

* Remove gitter webhooks

Basically reverting the gitter.im webhook integrations added in #36. Questions should now be redirected to https://forum.generic-mapping-tools.org.

* Change contact point to forum.generic-mapping-tools.org

Remove gitter.im contact point as it is not active anymore. Users should post questions/comments on the forum instead.

.codecov.yml

@@ -10,10 +10,5 @@ coverage:
         if_no_uploads: error
         if_not_found: success
         if_ci_failed: failure
-  notify:
-    gitter:
-      default:
-        url: "https://webhooks.gitter.im/e/42136d49f4c9c5fd2611"
-        threshold: 1%
 
 comment: off

.travis.yml

@@ -97,10 +97,3 @@ deploy:
 
 notifications:
     email: false
-    webhooks:
-        # Integration for Gitter
-        urls:
-            - https://webhooks.gitter.im/e/648c8355310c2ef3df4f
-        on_success: change  # options: [always|never|change] default: always
-        on_failure: always  # options: [always|never|change] default: always
-        on_start: never     # options: [always|never|change] default: always

README.rst

@@ -4,8 +4,7 @@ PyGMT
     A Python interface for the Generic Mapping Tools
 
 `Documentation (development version) <https://www.pygmt.org/dev>`__ |
-`Contact <https://gitter.im/GenericMappingTools/pygmt>`__ |
-`Forum <https://forum.generic-mapping-tools.org>`__
+`Contact <https://forum.generic-mapping-tools.org>`__ |
 
 .. image:: http://img.shields.io/pypi/v/pygmt.svg?style=flat-square
     :alt: Latest version on PyPI
@@ -25,9 +24,6 @@ PyGMT
 .. image:: https://img.shields.io/pypi/pyversions/pygmt.svg?style=flat-square
     :alt: Compatible Python versions.
     :target: https://pypi.python.org/pypi/pygmt
-.. image:: https://img.shields.io/gitter/room/GenericMappingTools/pygmt.svg?style=flat-square
-    :alt: Chat room on Gitter
-    :target: https://gitter.im/GenericMappingTools/pygmt
 .. image:: https://img.shields.io/discourse/status?label=forum&server=https%3A%2F%2Fforum.generic-mapping-tools.org%2F&style=flat-square
     :alt: Discourse forum
     :target: https://forum.generic-mapping-tools.org

doc/conf.py

@@ -144,7 +144,7 @@
         ),
         (
             '<i class="fa fa-comment fa-fw"></i> Contact',
-            "https://gitter.im/GenericMappingTools/pygmt",
+            "https://forum.generic-mapping-tools.org",
         ),
         (
             '<i class="fa fa-github fa-fw"></i> Source Code',