requirements: Adjust installation of Py3AMF module. (#920)

Move Py3AMF from setup.py load_requirements to requirements.txt

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Co-authored-by: Tessa Walsh <tessa@bitarchivist.net>

Author: Hellseher

requirements.txt

@@ -18,3 +18,4 @@ tldextract
 python-dateutil
 markupsafe>=2.1.1
 ua_parser
+py3AMF

setup.py

@@ -62,10 +62,6 @@ def generate_git_hash_py(pkg, filename='git_hash.py'):
 def load_requirements(filename):
     with open(filename, 'rt') as fh:
         requirements = fh.read().rstrip().split('\n')
-    if sys.version_info > (3, 0):
-        requirements.append("py3AMF")
-    else:
-        requirements.append("pyAMF")
     return requirements