Upload pdf fixes:

Handle no title
Handle no author
Fix import of more than one language
Add missing pdf upload publisher handling

setup.cfg

@@ -42,7 +42,7 @@ install_requires =
     backports_abc>=0.4
     Flask>=1.0.2,<1.2.0
     iso-639>=0.4.5,<0.5.0
-    PyPDF2>=1.26.0,<1.27.0
+    PyPDF3>=1.0.0,<1.0.4
     pytz>=2016.10
     requests>=2.11.1,<2.25.0
     SQLAlchemy>=1.3.0,<1.4.0
@@ -52,9 +52,9 @@ install_requires =
 
 [options.extras_require]
 gdrive =
-    google-api-python-client>=1.7.11,<1.8.0
-    gevent>=1.2.1,<20.6.0
-    greenlet>=0.4.12,<0.4.17
+    google-api-python-client>=1.7.11,<1.13.0
+    gevent>20.6.0,<21.2.0
+    greenlet>=0.4.17,<1.1.0
     httplib2>=0.9.2,<0.18.0
     oauth2client>=4.0.0,<4.1.4
     uritemplate>=3.0.0,<3.1.0
@@ -68,16 +68,16 @@ goodreads =
     goodreads>=0.3.2,<0.4.0
     python-Levenshtein>=0.12.0,<0.13.0
 ldap =
-    python-ldap>=3.0.0,<3.3.0
+    python-ldap>=3.0.0,<3.4.0
     Flask-SimpleLDAP>=1.4.0,<1.5.0
 oauth =
     Flask-Dance>=1.4.0,<3.1.0
     SQLAlchemy-Utils>=0.33.5,<0.37.0
 metadata =
-    lxml>=3.8.0,<4.6.0
+    lxml>=3.8.0,<4.7.0
     rarfile>=2.7
 comics =
-    natsort>=2.2.0
+    natsort>=2.2.0,<7.1.0
     comicapi>= 2.1.3,<2.2.0
 kobo =
     jsonschema>=3.2.0,<3.3.0