remove psutil (#773)

server/cli/launch.py

@@ -7,7 +7,6 @@ import warnings
 import webbrowser
 
 import click
-import psutil
 
 from server.app.app import Server
 from server.app.util.errors import ScanpyFileError
@@ -165,9 +164,6 @@ security risk by including the --scripts flag. Make sure you trust the scripts t
         click.echo(f"[cellxgene] Loading data from {basename(data)}, this may take awhile...")
     else:
         click.echo(f"[cellxgene] Loading data from {basename(data)}.")
-    # if file is larger than main memory, let the user know performance may suffer
-    if file_size > .95 * psutil.virtual_memory().total:
-        click.echo(f"[cellxgene] Warning: data file is larger than RAM - application may be very slow.")
 
     # Fix for anaconda python. matplotlib typically expects python to be installed as a framework TKAgg is usually
     # available and fixes this issue. See https://matplotlib.org/faq/virtualenv_faq.html

server/requirements.txt

@@ -9,7 +9,6 @@ flatbuffers>=1.10.0
 matplotlib>=2.2
 numpy>=1.15.2
 pandas>=0.23.1
-psutil>=5.6.2
 scanpy>=1.3.7
 scipy>=1.1.0,<1.3
 scikit-learn>=0.19.1,!=0.20.0