How to use Security and SecurityRequirement

[SOHELAHMED7]

Fixes#75

---

Current issues:

 'paths' => [
'/test' => new PathItem([
'get' => new Operation([
'security' => [new SecurityRequirement(['BearerAuth' => []])],
])
])
]

yields

'paths' => Array &1 (
'/test' => Array &2 (
'get' => Array &3 (
'security' => Array &4 (
0 => Array &5 (
'BearerAuth' => Array &6 ()
)
)
)
)
)

---

 'paths' => [
'/test' => new PathItem([
'get' => new Operation([
'security' => [new SecurityRequirement(['BearerAuth'])],
])
])
]

yields

'paths' => Array &1 (
'/test' => Array &2 (
'get' => Array &3 (
'security' => Array &4 (
0 => Array &5 (
0 => 'BearerAuth'
)
)
)
)
)

---

 'paths' => [
'/test' => new PathItem([
'get' => new Operation([
'security' => [
'BearerAuth' => new SecurityRequirement([])
],
])
])
]

yields

'paths' => Array &1 (
'/test' => Array &2 (
'get' => Array &3 (
'security' => Array &4 (
0 => Array &5 ()
)
)
)
)

This PR fixes above issues as

 'paths' => [
'/test' => new PathItem([
'get' => new Operation([
'security' => new SecurityRequirements([
'BearerAuth' => new SecurityRequirement([])
]),
])
])
]

yields

'paths' => Array &1 (
'/test' => Array &2 (
'get' => Array &3 (
'security' => Array &4 (
'BearerAuth' => Array &5 ( )
)
)
)
)

[cebe]

Thank you!