Change button styles from rounded to straight corners

This will create more visual consistency between the components
in the GUI since there are elements, such as text fields and
dropdowns that are styled with straight corners.

- Removes border radius from buttons
- Removes some redundant styles
- Adds input types that aren't currently inheriting
  defined styles

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I6ff1bde91e2e57df01484dd20003925cd914ffa2
diff --git a/app/common/styles/base/mixins.scss b/app/common/styles/base/mixins.scss
index ead5924..6b68114 100644
--- a/app/common/styles/base/mixins.scss
+++ b/app/common/styles/base/mixins.scss
@@ -47,11 +47,11 @@
 
 //Transitions mixin
 @mixin fastTransition-all {
-  transition: all 0.5s ease;
+  transition: all $duration--fast-02 ease;
 }
 
 @mixin slowTransition-all {
-  transition: all 1.5s ease;
+  transition: all $duration--slow-02 ease;
 }
 
 @mixin page-transition {