Fix typos of "environment"

docs/man-page/py.1

@@ -88,7 +88,7 @@ specified (must be formatted as `X.Y'; e.g.\ set \f[B]PY_PYTHON3\f[R] to
 Log details to stderr about how the Launcher is operating.
 .TP
 \f[B]VIRTUAL_ENV\f[R]
-Path to a directory containing virtual enviroment to use when no Python
+Path to a directory containing virtual environment to use when no Python
 version is explicitly requested; typically set by activating a virtual
 environment.
 .TP

docs/man-page/py.1.md

@@ -84,7 +84,7 @@ version is specified (must be formatted as 'X.Y'; e.g. set **PY_PYTHON3** to
 : Log details to stderr about how the Launcher is operating.
 
 **VIRTUAL_ENV**
-: Path to a directory containing virtual enviroment to use when no
+: Path to a directory containing virtual environment to use when no
 Python version is explicitly requested; typically set by
 activating a virtual environment.
 

src/HELP.txt

@@ -18,7 +18,7 @@ PY_PYTHON*    : Specify the version of Python to search for when only a major
                 version is specified (must be formatted as 'X.Y', e.g. set
                 `PY_PYTHON3` to `3.6` to cause `-3` to use Python 3.6).
 PYLAUNCH_DEBUG: Log details to stderr about how the Launcher is operating.
-VIRTUAL_ENV   : Path to a directory containing virtual enviroment to use when no
+VIRTUAL_ENV   : Path to a directory containing virtual environment to use when no
                 Python version is explicitly requested; typically set by
                 activating a virtual environment.
 

tests/common/mod.rs

@@ -88,7 +88,7 @@ pub struct EnvState {
 }
 
 impl EnvState {
-    /// Create a testing environement within the OS.
+    /// Create a testing environment within the OS.
     /// - Create two temp directories (referred to as `dir1` and `dir2` from now on)
     /// - `dir1/python2.7`
     /// - `dir1/python3.6`