Address prospector errors

Found while running pre-commit:

```shell
$ pre-commit run -av prospector

...

src/cffconvert/cli/rawify_url.py
  Line: 23
    pycodestyle: E201 / whitespace after '{' (col 60)
    pycodestyle: E202 / whitespace before '}' (col 66)

src/cffconvert/cli/read_from_url.py
  Line: 18
    pycodestyle: E201 / whitespace after '{' (col 52)
    pycodestyle: E202 / whitespace before '}' (col 58)

...
```

Author: kurtmckee

src/cffconvert/cli/rawify_url.py

@@ -20,7 +20,7 @@ def rawify_url(url):
                 # Proceed with making the call without authenticating -- stricter rate limits apply
                 pass
             else:
-                headers.update({"Authorization": f"Bearer { token }"})
+                headers.update({"Authorization": f"Bearer {token}"})
 
             try:
                 response = requests.get(repos_api, headers=headers, timeout=10)

src/cffconvert/cli/read_from_url.py

@@ -15,7 +15,7 @@ def read_from_url(url):
         # Proceed with making the call without authenticating -- stricter rate limits apply
         pass
     else:
-        headers.update({"Authorization": f"Bearer { token }"})
+        headers.update({"Authorization": f"Bearer {token}"})
     response = requests.get(url_raw, headers=headers, timeout=30)
     if response.ok:
         return response.text

src/cffconvert/lib/cff_1_x_x/authors/ris.py

@@ -138,19 +138,19 @@ def __init__(self, author):
         }
 
     def _from_alias(self):
-        return f"AU  - { self._author.get('alias') }\n"
+        return f"AU  - {self._author.get('alias')}\n"
 
     def _from_given_and_last(self):
-        return f"AU  - { self._get_full_last_name() }, { self._author.get('given-names') }\n"
+        return f"AU  - {self._get_full_last_name()}, {self._author.get('given-names')}\n"
 
     def _from_given(self):
-        return f"AU  - { self._author.get('given-names') }\n"
+        return f"AU  - {self._author.get('given-names')}\n"
 
     def _from_last(self):
-        return f"AU  - { self._get_full_last_name() }\n"
+        return f"AU  - {self._get_full_last_name()}\n"
 
     def _from_name(self):
-        return f"AU  - { self._author.get('name') }\n"
+        return f"AU  - {self._author.get('name')}\n"
 
     def as_string(self):
         key = self._get_key()

src/cffconvert/lib/cff_1_x_x/urls/bibtex.py

@@ -44,24 +44,24 @@ def __init__(self, cffobj):
     def _from_identifiers_url(self):
         urls = self._get_urls_from_identifiers()
         if len(urls) > 0:
-            return f"url = { '{' + urls[0].get('value') + '}' }"
+            return f"url = {{{urls[0].get('value')}}}"
         return None
 
     def _from_repository(self):
-        return f"url = { '{' + self._cffobj.get('repository') + '}' }"
+        return f"url = {{{self._cffobj.get('repository')}}}"
 
     def _from_repository_artifact(self):
-        return f"url = { '{' + self._cffobj.get('repository-artifact') + '}' }"
+        return f"url = {{{self._cffobj.get('repository-artifact')}}}"
 
     def _from_repository_code(self):
-        return f"url = { '{' + self._cffobj.get('repository-code') + '}' }"
+        return f"url = {{{self._cffobj.get('repository-code')}}}"
 
     @staticmethod
     def _from_thin_air():
         return None
 
     def _from_url(self):
-        return f"url = { '{' + self._cffobj.get('url') + '}' }"
+        return f"url = {{{self._cffobj.get('url')}}}"
 
     def as_string(self):
         key = "".join([

src/cffconvert/lib/cff_1_x_x/urls/ris.py

@@ -44,24 +44,24 @@ def __init__(self, cffobj):
     def _from_identifiers_url(self):
         urls = self._get_urls_from_identifiers()
         if len(urls) > 0:
-            return f"UR  - { urls[0].get('value') }\n"
+            return f"UR  - {urls[0].get('value')}\n"
         return None
 
     def _from_repository(self):
-        return f"UR  - { self._cffobj.get('repository') }\n"
+        return f"UR  - {self._cffobj.get('repository')}\n"
 
     def _from_repository_artifact(self):
-        return f"UR  - { self._cffobj.get('repository-artifact') }\n"
+        return f"UR  - {self._cffobj.get('repository-artifact')}\n"
 
     def _from_repository_code(self):
-        return f"UR  - { self._cffobj.get('repository-code') }\n"
+        return f"UR  - {self._cffobj.get('repository-code')}\n"
 
     @staticmethod
     def _from_thin_air():
         return None
 
     def _from_url(self):
-        return f"UR  - { self._cffobj.get('url') }\n"
+        return f"UR  - {self._cffobj.get('url')}\n"
 
     def as_string(self):
         key = "".join([