MNT: Replace master with main

CONTRIBUTING.rst

@@ -6,7 +6,7 @@ Overview
 
 Each tutorial is a `Jupyter notebook <http://jupyter.org/>`_ file. Each notebook is saved in a separate directory within the ``tutorials/notebooks``
 subdirectory in this project. For an example, let's look at the source notebook
-of the `FITS-header <https://github.com/astropy/astropy-tutorials/tree/master/tu
+of the `FITS-header <https://github.com/astropy/astropy-tutorials/tree/main/tu
 torials/notebooks/FITS-header/>`_ tutorial. Within
 ``tutorials/notebooks/FITS-header``, there is a single Jupyter notebook file
 that contains the text and code for the tutorial, and any small data files used
@@ -188,7 +188,7 @@ your ``requirements.txt`` file would look like:
     numpy>=1.13
 
 To see an example, have a look at the FITS-header `requirements.txt file <https:
-//github.com/astropy/astropy-tutorials/blob/master/tutorials/notebooks/FITS-head
+//github.com/astropy/astropy-tutorials/blob/main/tutorials/notebooks/FITS-head
 er/requirements.txt>`_.
 
 Push the notebook and other files from your local branch up to your fork of the
@@ -244,7 +244,7 @@ procedure:
 
   If you do this, the only change necessary when merging your notebook will be to set ``tutorialpath`` to  ``'http://data.astropy.org/tutorials/My-tutorial-name/'``.
 
-For larger data files that are bigger than 10 MB in size, we recommend hosting with Zenodo. 
+For larger data files that are bigger than 10 MB in size, we recommend hosting with Zenodo.
 To use this approach, follow these steps:
 
 * You will need to sign up for an account with Zenodo before you can upload a file there.

README.rst

@@ -22,7 +22,7 @@ You can also get started quickly using `Binder <http://mybinder.org>`_ to run th
 your web browser within a remote server:
 
 .. image:: http://mybinder.org/badge.svg
-    :target: https://mybinder.org/v2/gh/astropy/astropy-tutorials/master?filepath=tutorials/notebooks
+    :target: https://mybinder.org/v2/gh/astropy/astropy-tutorials/main?filepath=tutorials/notebooks
 
 
 Contributing tutorial material

scripts/tests/test_convert.py

@@ -10,7 +10,7 @@
 tests_path = path.split(path.abspath(__file__))[0]
 
 def test_convert_succeed():
-    # With the current master version of nbconvert, we can allow errors
+    # With the current main version of nbconvert, we can allow errors
     # per-cell. This notebook, even though it raises an exception, should still
     # execute fine:
     nbc = NBConverter(path.join(tests_path, 'test-succeed.ipynb'))

tutorials/astropy.tpl

@@ -8,7 +8,7 @@
 .. raw:: html
 
     <a href="../_static/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="download">Download tutorial notebook</button></a>
-    <a href="https://beta.mybinder.org/v2/gh/astropy/astropy-tutorials/master?filepath=/tutorials/notebooks/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="binder">Interactive tutorial notebook</button></a>
+    <a href="https://beta.mybinder.org/v2/gh/astropy/astropy-tutorials/main?filepath=/tutorials/notebooks/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="binder">Interactive tutorial notebook</button></a>
 
     <div id="spacer"></div>
 
@@ -31,7 +31,7 @@
     <div id="spacer"></div>
 
     <a href="../_static/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="download">Download tutorial notebook</button></a>
-    <a href="https://beta.mybinder.org/v2/gh/astropy/astropy-tutorials/master?filepath=/tutorials/notebooks/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="binder">Interactive tutorial notebook</button></a>
+    <a href="https://beta.mybinder.org/v2/gh/astropy/astropy-tutorials/main?filepath=/tutorials/notebooks/{{ nb_name }}/{{ nb_name }}.ipynb"><button id="binder">Interactive tutorial notebook</button></a>
 
 {% endblock %}
 

tutorials/dev.rst

@@ -8,7 +8,7 @@ Documentation on tutorials infrastructure
 Overview
 --------
 
-Tutorials are written as Jupyter notebooks on the ``master`` branch of the
+Tutorials are written as Jupyter notebooks on the ``main`` branch of the
 ``astropy/astropy-tutorials`` repository in ``tutorials/notebooks/``. These
 notebook files do not contain output in order to simplify version-controlling
 the files.
@@ -22,7 +22,7 @@ We use `CircleCI <https://circleci.com>`_ to do the Sphinx build, which is then
 pushed to the ``gh-pages`` branch of the repository and served by GitHub. The
 notebooks are first converted to RST files during the Sphinx build by doing the
 conversion at the end of the `Sphinx configuration file
-<https://github.com/astropy/astropy-tutorials/blob/master/tutorials/conf.py>`_.
+<https://github.com/astropy/astropy-tutorials/blob/main/tutorials/conf.py>`_.
 
 Why not use nbsphinx?
 ---------------------
@@ -73,7 +73,7 @@ Building the tutorials page locally
 -----------------------------------
 
 For this, you can use the `Makefile
-<https://github.com/astropy/astropy-tutorials/blob/master/Makefile>`_ at the
+<https://github.com/astropy/astropy-tutorials/blob/main/Makefile>`_ at the
 top-level of the tutorials repository. From the root level of the cloned or
 downloaded repository::
 
@@ -131,7 +131,7 @@ Marking a cell with an intentional error
 
 Edit the cell metadata of the cell in which you would like to raise an exception
 and add the following to the top-level JSON: ``"tags": ["raises-exception"]``
-This tag is recognized by the latest (master) version of nbconvert.
+This tag is recognized by the latest (main) version of nbconvert.
 
 Automatically Strip Output and Notebook Metadata
 ------------------------------------------------