Revert "Handle Fig not being installed"

This reverts commit 7ffe1f2.

I'm removing Fig because it caused issues with vim-tmux-runner [1] [2] [3].
The founders of Fig are trying to work with Chris Toomey to find a
solution though [3], so I could get it working if I really wanted to I bet.

For now, I'm just going to remove Fig; vim and tmux navigation is
more important.

The thing that attracted me to Fig was the command line autocomplete, but
I'm not sure that's worth the cost. Fig does a lot more than I actually
want it to, and it seems to be a fairly complex tool. Dealing with it doesn't
seem worth the value it would create for me. I'll pass.

[1]: christoomey/vim-tmux-navigator#339
[2]: christoomey/vim-tmux-navigator#317
[3]: christoomey/vim-tmux-navigator#295

.zshrc

@@ -1,7 +1,5 @@
 # Fig pre block. Keep at the top of this file.
-if [ -f "$HOME/.fig/shell/zshrc.pre.zsh" ]; then
-  . "$HOME/.fig/shell/zshrc.pre.zsh"
-fi
+. "$HOME/.fig/shell/zshrc.pre.zsh"
 
 export ZSH=~/.oh-my-zsh # Path to your oh-my-zsh installation.
 
@@ -212,6 +210,4 @@ test -e "${HOME}/.iterm2_shell_integration.zsh" && source "${HOME}/.iterm2_shell
 HEROKU_AC_ZSH_SETUP_PATH=~/Library/Caches/heroku/autocomplete/zsh_setup && test -f $HEROKU_AC_ZSH_SETUP_PATH && source $HEROKU_AC_ZSH_SETUP_PATH;
 
 # Fig post block. Keep at the bottom of this file.
-if [ -f "$HOME/.fig/shell/zshrc.post.zsh" ]; then
-  . "$HOME/.fig/shell/zshrc.post.zsh"
-fi
+. "$HOME/.fig/shell/zshrc.post.zsh"