made grassloper an application installable by `pip`.

also added install instructions

.gitignore

@@ -0,0 +1,3 @@
+grassloper/__pycache__
+grassloper.egg-info
+samples/TracTrac

README.md

@@ -2,3 +2,21 @@
 an application to estimate the slope of a granular surface flow
 
 
+# how to install
+
+`grassloper` is delivered as a simple pip application, and as such it can be installed from scratch using the following steps:
+
+```sh
+# create a python virtual environment (we name it name grassloper.venv)
+bob@stykades:~/work/grassloper$ python3 -m venv grassloper.venv  
+# activate the virtual environment to use it
+bob@stykades:~/work/grassloper$ source ./grassloper.venv/bin/activate
+# grassloper requires improtools https://github.com/g-raffy/improtools, which is not in pip's catalog
+# install improtools from its source directory (./improtools.git here, downloaded from https://github.com/g-raffy/improtools)
+(grassloper.venv) bob@stykades:~/work/grassloper$ pip install -e ./improtools.git
+# install grassloper from its source directory (./grassloper.git here)
+# this automatically installs the packages that grassloper depends on
+(grassloper.venv) bob@stykades:~/work/grassloper$ pip install -e ./grassloper.git
+# now that grassloper is installed in grassloper.venv and grassloper.venv is activated, simply run it using its command line 'grassloper'
+(grassloper.venv) bob@stykades:~/work/grassloper$ grassloper
+```

setup.py

@@ -0,0 +1,11 @@
+import setuptools
+
+setuptools.setup(
+    name="grassloper",
+    version="1.0",
+    packages=['grassloper'],
+    install_requires=['improtools(>=1.0)', 'numpy', 'opencv-python', 'scipy', 'h5py'],
+    entry_points={
+        'console_scripts': ['grassloper=grassloper.main:main', ]
+    },
+)