remove gmp from installation instructions

INSTALL.md

@@ -6,12 +6,11 @@ For usage instructions, please see the
 
 --------------------------------------------------------------------------------
 
-All releases require Python 2.7 to be installed before proceeding.
+All releases require Python 2.7+ or 3.4+ to be installed before proceeding.
 Mac OS X (10.7+) and Ubuntu ship with Python. Windows users without python 
 can download and install python from the [python 
-website](http://www.python.org/download/releases/2.7.8/).
+website](https://www.python.org/ftp/python/2.7.9/python-2.7.9.amd64.msi).
 
-Python 3 support is still considered experimental.
 
 #Installation of cobrapy
 
@@ -23,9 +22,9 @@ Python 3 support is still considered experimental.
 
 ### GNU/Linux
 0. [install pip] (http://pip.readthedocs.org/en/latest/installing.html).
-1. Install the python, glpk and gmp libraries. On debian-based
+1. Install the python and glpk development libraries. On debian-based
    systems (including Ubuntu and Mint), this can be done with
-   ```sudo apt-get install python-dev libglpk-dev libgmp-dev```
+   ```sudo apt-get install python-dev libglpk-dev```
 3. In a terminal, run ```sudo pip install cobra```
 
 ### Microsoft Windows
@@ -35,10 +34,10 @@ index](https://pypi.python.org/pypi/cobra/).
 
 
 ## Hacking version installation
-Use pip to install [Cython](http://cython.org/). Install libglpk and libgmp
-using your package manger. This would be ```brew install glpk gmp``` on a Mac
-and ```sudo apt-get install libglpk-dev libgmp-dev``` on debian-based systems
-(including Ubuntu and Mint). They can obviously also be compiled from the
+Use pip to install [Cython](http://cython.org/). Install libglpk 
+using your package manger. This would be ```brew install glpk``` on a Mac
+and ```sudo apt-get install libglpk-dev``` on debian-based systems
+(including Ubuntu and Mint). GLPK can also be compiled from the
 released source.
 
 Clone the git repository using your preferred mothod. Cloning from your
@@ -52,12 +51,12 @@ command:
 ## Optional Dependencies
 On windows, these can downloaded from [this site]
 (http://www.lfd.uci.edu/~gohlke/pythonlibs/). On Mac/Linux, they can be
-installed using pip, from binary installers, or from package managers.
+installed using pip, or from the OS package manager (e.g brew, apt, yum).
 
 1. [libsbml](http://sbml.org) >= 5.10 to read/write SBML files
   * [Windows installer](http://www.lfd.uci.edu/~gohlke/pythonlibs/#libsbml)
   * Use ```sudo pip install python-libsbml-experimental``` on Mac/Linux
-2. [numpy](http://numpy.org) >= 1.6.1 for double_deletion_analysis
+2. [numpy](http://numpy.org) >= 1.6.1 for double deletions
   * [Windows installer](http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy)
 3. [scipy](http://scipy.org) >= 0.11 for ArrayBasedModel and saving to *.mat files.
   * [Windows installer](http://www.lfd.uci.edu/~gohlke/pythonlibs/#scipy)
@@ -77,7 +76,7 @@ solvers:
  * [QSopt_ex esolver](http://www.dii.uchile.cl/~daespino/ESolver_doc/main.html)
  * [MOSEK](http://www.mosek.com/)
 
-ILOG/CPLEX and Gurobi are commercial software packages that, currently, 
+ILOG/CPLEX, MOSEK, and Gurobi are commercial software packages that currently 
 provide free licenses for academics and support both linear and quadratic 
 programming. GLPK is an opensource linear programming solver; however, it 
 does not support quadratic programming and is not as robust as the