Progressively upgrading python dependencies.

requirements.txt

@@ -1,7 +1,7 @@
-SQLAlchemy==0.8.4
+SQLAlchemy>=0.8.4,<0.9
 Flask==0.10.1
 Flask-Babel==0.9
-Flask-SQLAlchemy==1.0
+Flask-SQLAlchemy>=1.0,<2.0
 Flask-WTF==0.9.4
 Flask-Mail==0.9.0
 Flask-Cache==0.12
@@ -9,19 +9,19 @@ Jinja2==2.7.1
 MarkupSafe==0.18
 Werkzeug==0.9.4
 argparse==1.2.1
-itsdangerous==0.23
-wsgiref==0.1.2
+itsdangerous>=0.23
+wsgiref>=0.1.2
 blinker==1.3
-GeoAlchemy==0.7.2
-gevent==1.0.2
-jsonschema==2.3.0
-requests==2.1.0
+GeoAlchemy>=0.7.2
+gevent>=1.0.2,<1.2
+jsonschema>=2.3.0
+requests>=2.1.0
 # ndg & pyasn required for SNI
 -e git+https://code.ffdn.org/FFDN/ndg_httpsclient.git#egg=ndg-httpsclient
-pyasn1==0.1.7
-docutils==0.11
+pyasn1>=0.1.7
+docutils>=0.11
 # full-text search
-Whoosh==2.5.6
+Whoosh>=2.5.6
 # manage.py
 Flask-Script==0.6.6
 # isp format