Requirements updates (#422)

* Unpin requirements that do not need to be fixed

* add twine to dev requirements

* Add versions to dev too

server/requirements-dev.txt

@@ -1,4 +1,5 @@
-bumpversion
-pytest
-requests
+pytest>=3.6.3
+requests>=2.18.4
+twine>=1.12.1
+bumpversion>=0.5
 -r requirements.txt

server/requirements.txt

@@ -1,13 +1,13 @@
 anndata>=0.6.12
-click==6.7
+click>=6.7
 Flask>=1.0.2
-Flask-Caching==1.4.0
-Flask-Compress==1.4.0
-Flask-Cors==3.0.6
-Flask-RESTful==0.3.6
-flask-restful-swagger-2==0.35
-numpy==1.14.5
-pandas==0.23.1
-scanpy==1.3.2
-scipy==1.1.0
+Flask-Caching>=1.4.0
+Flask-Compress>=1.4.0
+Flask-Cors>=3.0.6
+Flask-RESTful>=0.3.6
+flask-restful-swagger-2>=0.35
+numpy>=1.14.5
+pandas>=0.23.1
+scanpy>=1.3.2
+scipy>=1.1.0
 scikit-learn==0.19.1