Implement automatic spell-check for docs (#688)

* [WIP] Implement automatic spell-check for docs

fixes #663

The only thing unclear to me so far is how the output of `make spelling`
should be checked - is there a possibility to check for a file (i.e.
`_build/spelling/output.txt`) to be empty, and report a failed build
otherwise?

* fix typo in requirements.txt

* add enchant library

* travis should report errors, order spelling wordlist

* change travis.yml to easier troubleshoot build issues

* fixed more typos, added more words

* add more words, fix more typos

* added more words

* added more words

* revert changes to .travis.yml

doc/api/resources/checkinlists.rst

@@ -165,7 +165,7 @@ Endpoints
 .. http:patch:: /api/v1/organizers/(organizer)/events/(event)/checkinlists/(id)/
 
    Update a check-in list. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to provide all fields of
-   the resource, other fields will be resetted to default. With ``PATCH``, you only need to provide the fields that you
+   the resource, other fields will be reset to default. With ``PATCH``, you only need to provide the fields that you
    want to change.
 
    You can change all fields of the resource except the ``id`` field and the ``checkin_count`` and ``position_count``

doc/api/resources/invoices.rst

@@ -221,5 +221,5 @@ Endpoints
    :statuscode 200: no error
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
-   :statuscode 409: The file is not yet ready and will now be prepared. Retry the request after waiting vor a few
+   :statuscode 409: The file is not yet ready and will now be prepared. Retry the request after waiting for a few
                     seconds.

doc/api/resources/items.rst

@@ -70,7 +70,7 @@ addons                                list of objects            Definition of a
 ├ addon_category                      integer                    Internal ID of the item category the add-on can be
                                                                  chosen from.
 ├ min_count                           integer                    The minimal number of add-ons that need to be chosen.
-├ max_count                           integer                    The maxima number of add-ons that can be chosen.
+├ max_count                           integer                    The maximal number of add-ons that can be chosen.
 └ position                            integer                    An integer, used for sorting
 ===================================== ========================== =======================================================
 

doc/api/resources/orders.rst

@@ -79,7 +79,7 @@ downloads                             list of objects            List of ticket
 
    The attributes ``invoice_address.vat_id_validated`` and ``invoice_address.is_business`` have been added.
    The attributes ``order.payment_fee``, ``order.payment_fee_tax_rate`` and ``order.payment_fee_tax_value`` have been
-   deprecated in favour of the new ``fees`` attribute but will still be served and removed in 1.9.
+   deprecated in favor of the new ``fees`` attribute but will still be served and removed in 1.9.
 
 .. versionchanged:: 1.9
 
@@ -342,7 +342,7 @@ Order endpoints
 
    Download tickets for an order, identified by its order code. Depending on the chosen output, the response might
    be a ZIP file, PDF file or something else. The order details response contains a list of output options for this
-   partictular order.
+   particular order.
 
    Tickets can be only downloaded if the order is paid and if ticket downloads are active. Note that in some cases the
    ticket file might not yet have been created. In that case, you will receive a status code :http:statuscode:`409` and

doc/api/resources/quotas.rst

@@ -158,7 +158,7 @@ Endpoints
 .. http:patch:: /api/v1/organizers/(organizer)/events/(event)/quotas/(id)/
 
    Update a quota. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to provide all fields of
-   the resource, other fields will be resetted to default. With ``PATCH``, you only need to provide the fields that you
+   the resource, other fields will be reset to default. With ``PATCH``, you only need to provide the fields that you
    want to change.
 
    You can change all fields of the resource except the ``id`` field.