fix: incorrect call to is_up

client/README.md

@@ -33,7 +33,7 @@ The response is the permanent URL where you can see the result of the capture.
 from pylookyloo import Lookyloo
 
 lookyloo = Lookyloo('https://url.of.lookyloo.instance')
-if lookyloo.is_up():  # to make sure it is up and reachable
+if lookyloo.is_up:  # to make sure it is up and reachable
 	permaurl = lookyloo.enqueue('http://url.to.lookup')
 
 ```

client/pylookyloo/__init__.py

@@ -14,7 +14,7 @@ def main():
     else:
         lookyloo = Lookyloo()
 
-    if lookyloo.is_up():
+    if lookyloo.is_up:
         url = lookyloo.enqueue(args.query)
         print(url)
     else:

client/pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pylookyloo"
-version = "0.6"
+version = "0.7"
 description = "Python client for Lookyloo"
 authors = ["Raphaël Vinot <raphael.vinot@circl.lu>"]
 license = "AGPL-3.0-or-later"