fix errors due to use of unportable == operator

The `==` operator is not defined by POSIX and many test(1) (also
spelled `[`) implementations do not support it.  Replace uses of
`==` with the POSIX-conformant `=` equality operator.

install-gitless.sh

@@ -5,11 +5,11 @@ function fatalExit (){
 }
 
 # an alternative URL that could be used: https://github.com/creationix/nvm/tarball/master
-if [ "$NVM_SOURCE" == "" ]; then
+if [ "$NVM_SOURCE" = "" ]; then
     NVM_SOURCE="https://raw.github.com/creationix/nvm/master/nvm.sh"
 fi
 
-if [ "$NVM_DIR" == "" ]; then
+if [ "$NVM_DIR" = "" ]; then
     NVM_DIR="$HOME/.nvm"
 fi
 

nvm.sh

@@ -351,7 +351,7 @@ nvm() {
     ;;
     "uninstall" )
       [ $# -ne 2 ] && nvm help && return
-      if [ $2 == `nvm_version` ]; then
+      if [ "$2" = `nvm_version` ]; then
         echo "nvm: Cannot uninstall currently-active node version, $2."
         return 1
       fi

test/fast/Running "nvm deactivate" should unset the nvm environment variables.

@@ -4,7 +4,7 @@ mkdir -p ../../v0.2.3
 
 die () { echo $@ ; exit 1; }
 
-[ `expr $PATH : ".*v0.2.3/.*/bin"` == 0 ] || echo "WARNING: Unexpectedly found v0.2.3 already active" >&2
+[ `expr $PATH : ".*v0.2.3/.*/bin"` = 0 ] || echo "WARNING: Unexpectedly found v0.2.3 already active" >&2
 
 . ../../nvm.sh
 nvm use v0.2.3 &&