Refactor HTTP common code (#207)

- move to common/http.py,
- make fetch_url return a Response.

src/php.py

@@ -1,4 +1,4 @@
-import json
+from common import http
 from common import dates
 from common import endoflife
 
@@ -7,8 +7,8 @@ PHP_MAJOR_VERSIONS = [4, 5, 7, 8]
 
 def fetch_versions(major_version):
     url = f"https://www.php.net/releases/index.php?json&max=-1&version={major_version}"
-    response = endoflife.fetch_url(url)
-    data = json.loads(response)
+    response = http.fetch_url(url)
+    data = response.json()
     for v in data:
         data[v] = dates.parse_date(data[v]["date"]).strftime("%Y-%m-%d")
         print(f"{v}: {data[v]}")